Amine-functionalized polymeric compositions for medical devices

ABSTRACT

The present disclosure provides amine-modified polymer foams, which may be used for wound dressing materials. For example, the modified materials can include a covalently attached molecule comprising free amine groups. Such amine groups can be used, for instance, to conjugate biologically active polypeptides and/or linkers. Methods for using modified polymers are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/438,565, filed Apr. 24, 2015; which is a National Stage ofInternational Application No. PCT/US2013/066671, filed Oct. 24, 2013;which claims priority to U.S. Provisional Application No. 61/718,131,filed Oct. 24, 2012, the disclosures of which are hereby incorporated byreference in their entirety.

FIELD

The present disclosure relates generally to functionalized polymericmaterial compositions, healing of wounds and wound-treatment therapies.More particularly, but not by way of limitation, the present disclosurerelates to modified materials, for example, amine-modified polyurethanefoams for use in binding biologically active components.

BACKGROUND INFORMATION

Clinical studies and practice have shown that providing a reducedpressure in proximity to a tissue site augments and accelerates thegrowth of new tissue at the tissue site. The applications of thisphenomenon are numerous, but application of reduced pressure has beenparticularly successful in treating wounds. This treatment (frequentlyreferred to in the medical community as “negative pressure woundtherapy,” “reduced pressure therapy,” or “vacuum therapy”) provides anumber of benefits, including faster healing and increased formulationof granulation tissue. One of the major clinical benefits of negativepressure wound therapy is its ability to effectively eliminate woundexudate, thereby reducing edema and allowing tissue decompression.However, in these processes the foams used for application of negativepressure therapy are typically biologically inert. In certain aspects itmay be beneficial to bind endogenous compounds at the wound site or toprovide biologically active compounds as a part of the foam. Improvedfoam materials with the ability to deliver and/or capture biologicallyactive components would therefore be desirable.

SUMMARY

The present disclosure provides novel polymeric materials, such aspolymeric foams including amine-modified polymers, which may be used toconstruct medical devices, coat medical devices, or as wound dressingmaterials. Such modified polymers can, in some aspects, be used to bindbiologically active components or agents, such as polypeptides, enzymes,or antimicrobials to the device.

Described herein are functionalized materials comprisingamine-functionalized polymers. Described herein are also functionalizedfoams comprising amine-functionalized polymers. Polymers that may befunctionalized with an amine group to covalently link to one or morebiologically active components or agents include but are not limited tohydrophobic or hydrophilic polyurethanes, crosslinked and/oruncrosslinked polyolefins, polyester, polyols, ethylene vinyl acetate(EVA), elastomers such as acrylonitrile butadiene (NBR), polychloroprene(PCP or CR), ethylene propylene rubber (EPR & EPDM), poloxamers,polyvinyl alcohols, polystyrenes, silicones, and/or fluoro carbonpolymers or a combination thereof. The polymer may be polyurethane. Thefunctionalized foam may be a polyurethane-based foam.

In one embodiment, the amine-functionalized foam may comprise a polymer,such as polyurethane, functionalized with: bifunctional branched ornon-branched hydroxyl-PEG-amine compounds ranging from 1 kDa to 60 kDa,bifunctional branched or non-branched amine-PEG-amine compounds rangingfrom 1 kDa to 60 kDa, bifunctional branched or non-branchedHOOC-PEG-amine compounds ranging from 1 kDa to 60 kDa, bifunctionalbranched or non-branched thiol-PEG-amine compounds ranging from 1 kDa to60 kDa, bifunctional branched or non-branched hydroxyl-polyol-aminecompounds ranging from 1 kDa to 60 kDa, bifunctional branched ornon-branched amine-polyol-amine compounds ranging from 1 kDa to 60 kDa,bifunctional branched or non-branched HOOC-polyol-amine compoundsranging from 1 kDa to 60 kDa, bifunctional branched or non-branchedthiol-polyol-amine compounds ranging from 1 kDa to 60 kDa,2-(Triethoxysilylpropoxy)ethoxysulfolane, Trimethylsilylmethyltrifluoromethane sulfonate, Trimethylsilylpropanesulfonic acid,Trimethylsilylmethanesulfonate, Trimethylsilyl isocyanate,N-(Trimethoxysilylpropyl) isothioronium chloride,2-(3-Trimethoxysilylpropylthio) thiophene, 2-(Trimethylsilyl)phenyltrifluoromethanesulfonate, Trimethylsilylchlorosulfonate,3-(Trihydroxysilyl)-1-Propanesulfonic acid,Trimethylsilylperfluoro-1-butanesulfonate,Trimethylsilyltrifluoromethanesulfonate,O-(2-Carboxyethyl)-O′-(2-mercaptoethyl)heptaethylene glycol, or anaminoglycoside. The aminoglycoside may be amikacin, apramycin,arbekacin, astromicin, bekanamycin, dibekacin, framycetin, gentamicin,hygromycin B, isepamicin, kanamycin, neomycin, netilmicin, paromomycin,rhodostreptomycin, ribostamycin, sisiomycin, streptomycin, tobramycin,and verdamicin, or a combination thereof. In other embodiments, thefunctionalized wound dressings provided herein comprise apolyurethane-based polymer foam comprising an aminoglycoside of formula(I):

wherein

R₁ is H or CH₂R₃;

R₂ is H or CH₂R₃;

R₃ is, each independently, NH₂, an amide linkage to a biologicallyactive component or agent, an amide linkage to an adapter, or an amidelinkage to one of the crosslinkers selected from Table 1; and

R₄ is, each independently, OH, or a carbamate linkage to thepolyurethane-based polymer foam.

In more specific embodiments at least 1 of the R₄ positions is each acarbamate linkage to the polyurethane-based polymer foam. Thepolyurethane-based polymer foam may comprise a plurality ofaminoglycosides of formula (I). In specific embodiments, theaminoglycosides may be present in the wound dressing at a ratio of fromabout 1 to about 40 parts per hundred of the polyurethane. Thebiologically active component or agent may be a therapeutic agent. Thetherapeutic agent may be a polypeptide.

In some specific embodiments, at least one of the R₃ positions is anamide linkage to a polypeptide. The R₃ positions can also comprise anamide linkage to one of the adapters selected from Table 1. Sometimes inthese embodiments, the adapter is further attached to a polypeptide,which in non-limiting examples may comprise a thioether linkage.Further, the adapter can be an EMCS-derived adapter or asulfo-EMCS-derived adapter. The polypeptide molecules may be an enzyme,a growth factor, chemokine, cytokine or a polypeptide that binds to agrowth factor, chemokine, or cytokine. The enzyme may be a debridementenzyme. Examples of debridement enzymes include but are not limitedbromelain, papain, trypsin, and collagenase. Debridement enzymes may beobtained from various sources, such as mammals or plants. As an example,bromelain may be obtained from pineapple.

In some cases, the polyurethane-based polymer foam is a reticulatedopen-celled foam. Further, the polyurethane-based polymer foam maycomprise one or more additional copolymers such as but not limited topolyvinyl alcohol, polypropylene, polystyrene, polyols, poloxamer, or acombination of one or more of these. The polyurethane-based polymer, inaddition to the aminoglycoside, may comprise one or more additionalcopolymers.

Provided herein are methods for treating a wound comprising contacting awound site with a functionalized wound dressing as described above. Thefunctionalized wound dressing may be used with negative pressure woundtherapy. The method may also involve applying an instillation solutionwith negative pressure wound therapy. Also provided are methods of usingthe wound dressing for debridement, biolfilm mitigation, and woundhealing. As an example, an enzyme for debridement, biofilm mitigation,and/or wound healing may be covalently attached to the functionalizedwound dressing to create a multifunctional wound dressing.

Described herein are functionalized material and foam comprising apolymer copolymerized with a amine-polyol or amine-polyethylene glycol(PEG). The functionalized material or foam may be covalently attachedwith an adapter and/or a crosslinker. The functionalized material orfoam may also be covalently attached with a crosslinker through theadapter on the material or foam. The biologically active agent may beattached to the functionalized material or foam through the crosslinker.

Further, some embodiments relate to methods of producing a wounddressing, comprising copolymerizing a diisocyanate and anaminoglycoside. Specific embodiments of these methods may comprisecopolymerizing a diisocyanate, an aminoglycoside, and a polyol. In suchcases, the aminoglycoside copolymer can be any useful aminoglycoside,including but not limited to neomycin, amikacin, arbekacin, gentamicin,kanamycin, netilmicin, paromomycin, rhodostreptomycin, streptomycin,tobramycin, framycetin or apramycin.

The materials described herein comprise a polyurethane-based material,sheet, solid or semi-solid membrane, permeable or semi-permeablemembrane, interfacial layer. The polyurethane-based material may also beused as a coating for beads, catheter, stent, or other devices

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings illustrate by way of example and not limitation.For the sake of brevity and clarity, every feature of a given structureis not always labeled in every figure in which that structure appears.Identical reference numbers do not necessarily indicate an identicalstructure. Rather, the same reference number may be used to indicate asimilar feature or a feature with similar functionality, as maynon-identical reference numbers.

FIG. 1 depicts a side view of one embodiment of a wound dressings of theembodiments having one of the present modified wound inserts and coupledto a wound site and to a wound treatment apparatus.

FIG. 2 depicts an enlarged side view of the modified wound insert ofFIG. 2.

FIG. 3 depicts a schematic block diagram of one embodiment of a woundtreatment apparatus that can comprise and/or be coupled to and/or beused with the present wound dressings and/or modified wound inserts.

FIG. 4 depicts the structure of neomycin. Neomycin contains —OH groups,that can be used as a polyol in the synthesis of polyurethane.Meanwhile, the —NH₂ groups remain unreacted during polyurethanesynthesis, leaving the primary amines accessible for further chemicalreactions.

FIG. 5 depicts 100× scanning electron microscope (SEM) images of ROCF inneomycin foam. SEM images illustrate the presence of ROCF in the 5 phrand 10 phr foams.

FIG. 6 depicts the results of studies assessing of amine reactivity ofneomycin-modified foams. Fluorescence was quantified for each treatmentcondition and is indicated in the bottom panel.

FIGS. 7A AND 7B depict SEM analysis of the Enzyme Protease Dressing(EPD) at 250×. FIG. 7A shows uncoated amine-functionalized foam withsmooth struts and surfaces.

FIG. 7B shows the amine-functionalized foam with covalently bound enzymematrices (arrows).

FIG. 8 depicts biochemical tests comparing EPD activity and 6.25 μMbromelain standard.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Provided herein are amine-functionalized foams, which may be used forwound dressings. Various polymers may be modified with an amine group tobecome an amine-functionalized foam for use as a wound dressing.Examples of such polymers include but are not limited polyurethane. Incertain embodiments modified foams are provided that comprise an aminefunctionalization of polyurethane. Such amine functionalizations,provide for the covalent binding of various biologically activecomponents to the foams. In some aspects, foams modified to include anamine moiety can be used to link molecules (e.g., therapeutic agentssuch as peptides or polypeptide) that facilitate the capture ofbiomolecules, drug/antimicrobial/nanoparticle delivery,detection/diagnostics, regulation of the wound environment, and possiblybiodegradation. For example, in some aspects, an amine functionalizedfoam can be produced by copolymerization of an aminoglycoside (i.e.,molecules comprising several amino sugars connected by glycoside bonds),such as neomycin (FIG. 4), with a diisocyanate (e.g., toluenediisocyanate). The resulting amine-modified foams include free aminepositions that can be further modified for linkage to biologicallyactive components or agents. An example of such an amine moiety forfunctionalization of foams is neomycin(2S,3S,4S,5R)-5-amino-2-(aminomethyl)-6-((2R,3S,4R,5S)-5-((1R,2R,5R,6R)-3,5-diamino-2-((2R,3S,4R,5S)-3-amino-6-(aminomethyl)-4,5-dihydroxytetrahydro-2H-pyran-2-yloxy)-6-hydroxycyclohexyloxy)-4-hydroxy-2-(hydroxymethyl)tetrahydrofuran-3-yloxy)tetrahydro-2H-pyran-3,4-diol,hereforth referred to as “aminoglycoside”, and structurally depicted as:

where

R₁ is H or CH₂R₃;

R₂ is H or CH₂R₃;

R₃ represents free NH₂ positions or positions that can be occupied by abiologically active component, such as a polypeptide, attached by anadapter or crosslinker.

R₄ represents OH positions, some of which, can provide a carbamatelinkage to the polyurethane-based polymer foam.

In certain embodiments, wound dressings comprising a functionalized foamare provided. The foam may comprise polyurethane foam functionalizedwith an aminoglycoside having a free amine position for linkage tobiologically active component or agent. Examples of aminoglycosideinclude but are not limited to amikacin, apramycin, arbekacin,astromicin, bekanamycin, dibekacin, framycetin, gentamicin, hygromycinB, isepamicin, kanamycin, neomycin, netilmicin, paromomycin,rhodostreptomycin, ribostamycin, sisiomycin, streptomycin, tobramycin,verdamicin, and salts thereof. An example of a salt of an aminoglycosideis paromomycin sulfate

Studies detailed below confirm that such amine-modified foams wererobust and retained a reticulated open cell structure (FIG. 5).Importantly, the foams were able to withstand 40 Kgy gammasterilization, a crucial feature for any wound dressing material. Thesestudies also confirmed, by dye-binding studies, that free aminepositions were present through-out the foams (FIG. 6). Thus,aminoglycosides such as, neomycin polymerized well with isocyanatechemistry acting effectively as a polyol in the reaction. When thereaction occurs, the —OH groups polymerize with isocyanate, but theprimary amine groups (NH₂) remain partially unreacted for furtherchemical reactions.

Free amine positions on the modified foams detailed herein can beattached to biologically active molecules by a variety of well knownchemistries. For example, any of the adapter molecules provided in Table1 can be used for covalent attachment of biologically active componentsor agents, such as polypeptides. The four main chemistries being amine,sulfhydryl, non-selective and carboxyl. Finally, amine-functionalizedfoams can be used for direct conjugation that does not require acrosslinker, such as the bond formed between a primary amine group and acarboxylic acid in a peptide bond.

The amine-modified foams of the embodiments therefore provide platformsfor capture of biomolecules; drug/antimicrobial/nanoparticle delivery;detection/diagnostics (e.g., of bound components); regulation of thewound environment; and/or biodegradation/reabsorption

A. Definitions

When used in the context of a chemical group, “hydrogen” means —H;“hydroxy” means —OH; “oxo” means ═O; “halo” means independently —F, —Cl,—Br or —I; “amino” means —NH₂ (see below for definitions of groupscontaining the term amino, e.g., alkylamino); “hydroxyamino” means—NHOH; “nitro” means —NO₂; imino means ═NH (see below for definitions ofgroups containing the term imino, e.g., alkylimino); “cyano” means —CN;“azido” means —N₃; in a monovalent context “phosphate” means —OP(O)(OH)₂or a deprotonated form thereof; in a divalent context “phosphate” means—OP(O)(OH)O— or a deprotonated form thereof; “mercapto” means —SH;“thio” means ═S; “thioether” means —S—; “sulfonamido” means —NHS(O)₂—(see below for definitions of groups containing the term sulfonamido,e.g., alkylsulfonamido); “sulfonyl” means —S(O)₂— (see below fordefinitions of groups containing the term sulfonyl, e.g.,alkylsulfonyl); and “sulfinyl” means —S(O)— (see below for definitionsof groups containing the term sulfinyl, e.g., alkylsulfinyl).

The symbol “—” means a single bond, “═” means a double bond, and “≡”means triple bond. The symbol “----” represents an optional bond, whichif present is either single or double. The symbol “

” represents a single bond or a double bond. Thus, for example, thestructure

includes the structures

As will be understood by a person of skill in the art, no one such ringatom forms part of more than one double bond. The symbol “

”, when drawn perpendicularly across a bond indicates a point ofattachment of the group. It is noted that the point of attachment istypically only identified in this manner for larger groups in order toassist the reader in rapidly and unambiguously identifying a point ofattachment. The symbol “

” means a single bond where the group attached to the thick end of thewedge is “out of the page.” The symbol “

” means a single bond where the group attached to the thick end of thewedge is “into the page”. The symbol “

” means a single bond where the conformation (e.g., either R or S) orthe geometry is undefined (e.g., either E or Z).

Any undefined valency on an atom of a structure shown in thisapplication implicitly represents a hydrogen atom bonded to the atom.When a group “R” is depicted as a “floating group” on a ring system, forexample, in the formula:

then R may replace any hydrogen atom attached to any of the ring atoms,including a depicted, implied, or expressly defined hydrogen, so long asa stable structure is formed. When a group “R” is depicted as a“floating group” on a fused ring system, as for example in the formula:

then R may replace any hydrogen attached to any of the ring atoms ofeither of the fused rings unless specified otherwise. Replaceablehydrogens include depicted hydrogens (e.g., the hydrogen attached to thenitrogen in the formula above), implied hydrogens (e.g., a hydrogen ofthe formula above that is not shown but understood to be present),expressly defined hydrogens, and optional hydrogens whose presencedepends on the identity of a ring atom (e.g., a hydrogen attached togroup X, when X equals —CH—), so long as a stable structure is formed.In the example depicted, R may reside on either the 5-membered or the6-membered ring of the fused ring system. In the formula above, thesubscript letter “y” immediately following the group “R” enclosed inparentheses, represents a numeric variable. Unless specified otherwise,this variable can be 0, 1, 2, or any integer greater than 2, onlylimited by the maximum number of replaceable hydrogen atoms of the ringor ring system.

For the groups and classes below, the following parenthetical subscriptsfurther define the group/class as follows: “(Cn)” defines the exactnumber (n) of carbon atoms in the group/class. “(C≦n)” defines themaximum number (n) of carbon atoms that can be in the group/class, withthe minimum number as small as possible for the group in question, e.g.,it is understood that the minimum number of carbon atoms in the group“alkenyl_((C≦8))” or the class “alkene_((C≦8))” is two. For example,“alkoxy_((C≦10))” designates those alkoxy groups having from 1 to 10carbon atoms (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, or any rangederivable therein (e.g., 3 to 10 carbon atoms). (Cn-n′) defines both theminimum (n) and maximum number (n′) of carbon atoms in the group.Similarly, “alkyl_((C2-10))” designates those alkyl groups having from 2to 10 carbon atoms (e.g., 2, 3, 4, 5, 6, 7, 8, 9, or 10, or any rangederivable therein (e.g., 3 to 10 carbon atoms)).

The term “saturated” as used herein means the compound or group somodified has no carbon-carbon double and no carbon-carbon triple bonds,except as noted below. The term does not preclude carbon-heteroatommultiple bonds, for example a carbon oxygen double bond or a carbonnitrogen double bond. Moreover, it does not preclude a carbon-carbondouble bond that may occur as part of keto-enol tautomerism orimine/enamine tautomerism.

The term “aliphatic” when used without the “substituted” modifiersignifies that the compound/group so modified is an acyclic or cyclic,but non-aromatic hydrocarbon compound or group. In aliphaticcompounds/groups, the carbon atoms can be joined together in straightchains, branched chains, or non-aromatic rings (alicyclic). Aliphaticcompounds/groups can be saturated, that is joined by single bonds(alkanes/alkyl), or unsaturated, with one or more double bonds(alkenes/alkenyl) or with one or more triple bonds (alkynes/alkynyl).When the term “aliphatic” is used without the “substituted” modifieronly carbon and hydrogen atoms are present. When the term is used withthe “substituted” modifier one or more hydrogen atom has beenindependently replaced by —OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H,—CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or—OC(O)CH₃.

The term “alkyl” when used without the “substituted” modifier refers toa monovalent saturated aliphatic group with a carbon atom as the pointof attachment, a linear or branched, cyclo, cyclic or acyclic structure,and no atoms other than carbon and hydrogen. Thus, as used hereincycloalkyl is a subset of alkyl. The groups —CH₃ (Me), —CH₂CH₃ (Et),—CH₂CH₂CH₃ (n-Pr), —CH(CH₃)₂ (iso-Pr), —CH(CH₂)₂ (cyclopropyl),—CH₂CH₂CH₂CH₃ (n-Bu), —CH(CH₃)CH₂CH₃ (sec-butyl), —CH₂CH(CH₃)₂(iso-butyl), —C(CH₃)₃ (tert-butyl), —CH₂C(CH₃)₃ (neo-pentyl),cyclobutyl, cyclopentyl, cyclohexyl, and cyclohexylmethyl arenon-limiting examples of alkyl groups. The term “alkanediyl” when usedwithout the “substituted” modifier refers to a divalent saturatedaliphatic group, with one or two saturated carbon atom(s) as thepoint(s) of attachment, a linear or branched, cyclo, cyclic or acyclicstructure, no carbon-carbon double or triple bonds, and no atoms otherthan carbon and hydrogen. The groups, —CH₂— (methylene), —CH₂CH₂—,—CH₂C(CH₃)₂CH₂—, —CH₂CH₂CH₂—, and

are non-limiting examples of alkanediyl groups. The term “alkylidene”when used without the “substituted” modifier refers to the divalentgroup ═CRR′ in which R and R′ are independently hydrogen, alkyl, or Rand R′ are taken together to represent an alkanediyl having at least twocarbon atoms. Non-limiting examples of alkylidene groups include: ═CH₂,═CH(CH₂CH₃), and ═C(CH₃)₂. When any of these terms is used with the“substituted” modifier one or more hydrogen atom has been independentlyreplaced by —OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH,—OCH₃, —OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃. Thefollowing groups are non-limiting examples of substituted alkyl groups:—CH₂OH, —CH₂C1, —CF₃, —CH₂CN, —CH₂C(O)OH, —CH₂C(O)OCH₃, —CH₂C(O)NH₂,—CH₂C(O)CH₃, —CH₂OCH₃, —CH₂OC(O)CH₃, —CH₂NH₂, —CH₂N(CH₃)₂, and—CH₂CH₂C1. The term “fluoroalkyl” is a subset of substituted alkyl, inwhich one or more hydrogen has been substituted with a fluoro group andno other atoms aside from carbon, hydrogen and fluorine are present. Thegroups, —CH₂F, —CF₃, and —CH₂CF₃ are non-limiting examples offluoroalkyl groups. An “alkane” refers to the compound H—R, wherein R isalkyl.

The term “alkenyl” when used without the “substituted” modifier refersto an monovalent unsaturated aliphatic group with a carbon atom as thepoint of attachment, a linear or branched, cyclo, cyclic or acyclicstructure, at least one nonaromatic carbon-carbon double bond, nocarbon-carbon triple bonds, and no atoms other than carbon and hydrogen.Non-limiting examples of alkenyl groups include: —CH═CH₂ (vinyl),—CH═CHCH₃, —CH═CHCH₂CH₃, —CH₂CH═CH₂ (allyl), —CH₂CH═CHCH₃, and—CH═CH—C₆H₅. The term “alkenediyl” when used without the “substituted”modifier refers to a divalent unsaturated aliphatic group, with twocarbon atoms as points of attachment, a linear or branched, cyclo,cyclic or acyclic structure, at least one nonaromatic carbon-carbondouble bond, no carbon-carbon triple bonds, and no atoms other thancarbon and hydrogen. The groups, —CH═CH—, —CH═C(CH₃)CH₂—, —CH═CHCH₂—,and

are non-limiting examples of alkenediyl groups. When these terms areused with the “substituted” modifier one or more hydrogen atom has beenindependently replaced by —OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H,—CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or—OC(O)CH₃. The groups, —CH═CHF, —CH═CHCl and —CH═CHBr, are non-limitingexamples of substituted alkenyl groups. An “alkene” refers to thecompound H—R, wherein R is alkenyl.

The term “aryl” when used without the “substituted” modifier refers to amonovalent unsaturated aromatic group with an aromatic carbon atom asthe point of attachment, said carbon atom forming part of a one or moresix-membered aromatic ring structure, wherein the ring atoms are allcarbon, and wherein the group consists of no atoms other than carbon andhydrogen. If more than one ring is present, the rings may be fused orunfused. As used herein, the term does not preclude the presence of oneor more alkyl group (carbon number limitation permitting) attached tothe first aromatic ring or any additional aromatic ring present.Non-limiting examples of aryl groups include phenyl (Ph), methylphenyl,(dimethyl)phenyl, —C₆H₄CH₂CH₃ (ethylphenyl), naphthyl, and themonovalent group derived from biphenyl. The term “arenediyl” when usedwithout the “substituted” modifier refers to a divalent aromatic group,with two aromatic carbon atoms as points of attachment, said carbonatoms forming part of one or more six-membered aromatic ringstructure(s) wherein the ring atoms are all carbon, and wherein themonovalent group consists of no atoms other than carbon and hydrogen. Asused herein, the term does not preclude the presence of one or morealkyl group (carbon number limitation permitting) attached to the firstaromatic ring or any additional aromatic ring present. If more than onering is present, the rings may be fused or unfused. Non-limitingexamples of arenediyl groups include:

When these terms are used with the “substituted” modifier one or morehydrogen atom has been independently replaced by —OH, —F, —Cl, —Br, —I,—NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃,—N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃. An “arene” refers to the compound H—R,wherein R is aryl.

The term “aralkyl” when used without the “substituted” modifier refersto the monovalent group -alkanediyl-aryl, in which the terms alkanediyland aryl are each used in a manner consistent with the definitionsprovided above. Non-limiting examples of aralkyls are: phenylmethyl(benzyl, Bn) and 2-phenyl-ethyl. When the term is used with the“substituted” modifier one or more hydrogen atom from the alkanediyland/or the aryl has been independently replaced by —OH, —F, —Cl, —Br,—I, —NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃,—N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃. Non-limiting examples of substitutedaralkyls are: (3-chlorophenyl)-methyl, and 2-chloro-2-phenyl-eth-1-yl.

The term “heteroaryl” when used without the “substituted” modifierrefers to a monovalent aromatic group with an aromatic carbon atom ornitrogen atom as the point of attachment, said carbon atom or nitrogenatom forming part of an aromatic ring structure wherein at least one ofthe ring atoms is nitrogen, oxygen or sulfur, and wherein the groupconsists of no atoms other than carbon, hydrogen, aromatic nitrogen,aromatic oxygen and aromatic sulfur. As used herein, the term does notpreclude the presence of one or more alkyl group (carbon numberlimitation permitting) attached to the aromatic ring or any additionalaromatic ring present. Non-limiting examples of heteroaryl groupsinclude furanyl, imidazolyl, indolyl, indazolyl (Im), methylpyridyl,oxazolyl, pyridyl, pyrrolyl, pyrimidyl, pyrazinyl, quinolyl, quinazolyl,quinoxalinyl, thienyl, and triazinyl. The term “heteroarenediyl” whenused without the “substituted” modifier refers to an divalent aromaticgroup, with two aromatic carbon atoms, two aromatic nitrogen atoms, orone aromatic carbon atom and one aromatic nitrogen atom as the twopoints of attachment, said atoms forming part of one or more aromaticring structure(s) wherein at least one of the ring atoms is nitrogen,oxygen or sulfur, and wherein the divalent group consists of no atomsother than carbon, hydrogen, aromatic nitrogen, aromatic oxygen andaromatic sulfur. As used herein, the term does not preclude the presenceof one or more alkyl group (carbon number limitation permitting)attached to the first aromatic ring or any additional aromatic ringpresent. If more than one ring is present, the rings may be fused orunfused. Non-limiting examples of heteroarenediyl groups include:

When these terms are used with the “substituted” modifier one or morehydrogen atom has been independently replaced by —OH, —F, —Cl, —Br, —I,—NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃,—N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃.

The term “acyl” when used without the “substituted” modifier refers tothe group —C(O)R, in which R is a hydrogen, alkyl, aryl, aralkyl orheteroaryl, as those terms are defined above. The groups, —CHO, —C(O)CH₃(acetyl, Ac), —C(O)CH₂CH₃, —C(O)CH₂CH₂CH₃, —C(O)CH(CH₃)₂, —C(O)CH(CH₂)₂,—C(O)C₆H₅, —C(O)C₆H₄CH₃, —C(O)CH₂C₆H₅, —C(O)(imidazolyl) arenon-limiting examples of acyl groups. A “thioacyl” is defined in ananalogous manner, except that the oxygen atom of the group —C(O)R hasbeen replaced with a sulfur atom, —C(S)R. When either of these terms areused with the “substituted” modifier one or more hydrogen atom has beenindependently replaced by —OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H,—CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or—OC(O)CH₃. The groups, —C(O)CH₂CF₃, —CO₂H (carboxyl), —CO₂CH₃(methylcarboxyl), —CO₂CH₂CH₃, —C(O)NH₂ (carbamoyl), and —CON(CH₃)₂, arenon-limiting examples of substituted acyl groups.

The term “alkoxy” when used without the “substituted” modifier refers tothe group —OR, in which R is an alkyl, as that term is defined above.Non-limiting examples of alkoxy groups include: —OCH₃, —OCH₂CH₃,—OCH₂CH₂CH₃, —OCH(CH₃)₂, —OCH(CH₂)₂, —O-cyclopentyl, and —O-cyclohexyl.The terms “alkenyloxy”, “alkynyloxy”, “aryloxy”, “aralkoxy”,“heteroaryloxy”, and “acyloxy”, when used without the “substituted”modifier, refers to groups, defined as —OR, in which R is alkenyl,alkynyl, aryl, aralkyl, heteroaryl, and acyl, respectively. Similarly,the term “alkylthio” when used without the “substituted” modifier refersto the group —SR, in which R is an alkyl, as that term is defined above.The term “alkoxydiyl” when used without the “substituted” modifierrefers to the divalent group —O— alkanediyl-. When any of these terms isused with the “substituted” modifier one or more hydrogen atom has beenindependently replaced by —OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H,—CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or—OC(O)CH₃. The term “alcohol” corresponds to an alkane, as definedabove, wherein at least one of the hydrogen atoms has been replaced witha hydroxy group.

The term “alkylamino” when used without the “substituted” modifierrefers to the group —NHR, in which R is an alkyl, as that term isdefined above. Non-limiting examples of alkylamino groups include:—NHCH₃ and —NHCH₂CH₃. The term “dialkylamino” when used without the“substituted” modifier refers to the group —NRR′, in which R and R′ canbe the same or different alkyl groups, or R and R′ can be taken togetherto represent an alkanediyl. Non-limiting examples of dialkylamino groupsinclude: —N(CH₃)₂, —N(CH₃)(CH₂CH₃), and N-pyrrolidinyl. The terms“alkoxyamino”, “alkenylamino”, “alkynylamino”, “arylamino”,“aralkylamino”, “heteroarylamino”, and “alkylsulfonylamino” when usedwithout the “substituted” modifier, refers to groups, defined as —NHR,in which R is alkoxy, alkenyl, alkynyl, aryl, aralkyl, heteroaryl, andalkylsulfonyl, respectively. A non-limiting example of an arylaminogroup is —NHC₆H₅. The term “amido” (acylamino), when used without the“substituted” modifier, refers to the group —NHR, in which R is acyl, asthat term is defined above. A non-limiting example of an amido group is—NHC(O)CH₃. The term “alkylimino” when used without the “substituted”modifier refers to the divalent group ═NR, in which R is an alkyl, asthat term is defined above. When any of these terms is used with the“substituted” modifier one or more hydrogen atom has been independentlyreplaced by —OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH,—OCH₃, —OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃. The groups—NHC(O)OCH₃ and —NHC(O)NHCH₃ are non-limiting examples of substitutedamido groups.

The terms “alkylsulfonyl” and “alkylsulfinyl” when used without the“substituted” modifier refers to the groups —S(O)₂R and —S(O)R,respectively, in which R is an alkyl, as that term is defined above. Theterms “alkenylsulfonyl”, “alkynylsulfonyl”, “arylsulfonyl”,“aralkylsulfonyl”, and “heteroarylsulfonyl”, are defined in an analogousmanner. When any of these terms is used with the “substituted” modifierone or more hydrogen atom has been independently replaced by —OH, —F,—Cl, —Br, —I, —NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH, —OCH₃, —OCH₂CH₃,—C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃.

The term “glycoside” refers to a compound in which a sugar group isbound to a non-carbohydrate moiety. Typically the sugar group (glycone)is bonded through its anomeric carbon to another group (aglycone) via aglycosidic bond that has an oxygen, nitrogen or sulfur atom as a linker.

A “simple sugar” is the basic structural unit of carbohydrates, whichcannot be readily hydrolyzed into simpler units. The elementary formulaof a simple monosaccharide is C_(n)H_(2n)O_(n), where the integer n isat least 3 and rarely greater than 7. Simple monosacharides may be namedgenerically according on the number of carbon atoms n: trioses,tetroses, pentoses, hexoses, etc. Simple sugars may be open chain(acyclic), cyclic or mixtures thereof. In these cyclic forms, the ringusually has 5 or 6 atoms. These forms are called furanoses andpyranoses, respectively by analogy with furan and pyran. Simple sugarsmay be further classified into aldoses, those with a carbonyl group atthe end of the chain in the acyclic form, and ketoses, those in whichthe carbonyl group is not at the end of the chain. Non-limiting examplesof aldoses include: glycolaldehyde, glyceraldehydes, erythrose, threose,ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose,gulose, idose, galactose and talose. Non-limiting examples of aldosesinclude: dihydroxyacetone, erythrulose, ribulose, xylulose, fructose,psicose, sorbose and tagatose. The ‘D-’ and ‘L-’ prefixes may be used todistinguish two particular stereoisomers which are mirror-images of eachother. The term simple sugar also covers O-acetyl derivatives thereof.

An “amino sugar” or “aminoglycoside” refers to a derivative of a sugar,deoxy sugar, sugar acid or sugar alcohol, where one or more hydroxygroup(s) has been replace with one more amino group(s). An “amino sugar”refers to a derivative of a simple sugar, simply deoxy sugar, simplysugar acid or sugar alcohol, where one or more hydroxy group(s) has beenreplaced with one more amino group(s). These terms also cover N- andO-acetyl derivatives thereof. Non-limiting examples includeN-acetylglucosamine, galactosamine, glucosamine and sialic acid.

The term “deoxy sugar” refers to a sugar derivative where one of thehydroxy groups of a carbohydrate has been replaced with a hydrogen atom.A “simple deoxy sugar” is a deoxy sugar derived from a simple sugar, asdefined herein. These terms also cover O-acetyl derivatives thereof.Non-limiting examples of simple deoxy sugars are deoxyribose (based uponribose), fucose, and rhamnose.

The term “sugar acid” refers to a sugar derivative where an aldehydefunctional group or one or more hydroxy functional groups has beenoxidized to a carboxyl group. Aldonic acids are those in which thealdehyde functional group of an aldose has been oxidized. Ulosonic acidsare those in which the first hydroxyl group of a 2-ketose has beenoxidized creating an α-ketoacid. Uronic acids are those in which theterminal hydroxyl group of an aldose or ketose has been oxidized.Aldaric acids are those in which both ends of an aldose have beenoxidized. Non-limiting aldonic acids include glyceric acid (3C), xylonicacid (5C), gluconic acid (6C), and ascorbic acid (6C, unsaturatedlactone). Non-limiting examples of ulosonic acids include neuraminicacid (5-amino-3,5-dideoxy-D-glycero-D-galacto-non-2-ulosonic acid) andketodeoxyoctulosonic acid (KDO or 3-deoxy-D-manno-oct-2-ulosonic acid).Non-limiting examples of uronic acids include glucuronic acid (6C),galacturonic acid (6C), and iduronic acid (6C). Non-limiting example ofaldaric acids include tartaric acid (4C), meso-galactaric acid (mucicacid) (6C), and D-glucaric acid (saccharic acid) (6C). A “simple sugaracid” is a sugar acid derived from a simple sugar. These terms alsocover O-acetyl derivatives thereof.

The term “sugar alcohol” refers to a sugar derivative whose carbonylgroup (aldehyde or ketone, reducing sugar) has been reduced to a primaryor secondary hydroxyl group. Non-limiting examples of sugar alcoholsinclude: glycol (2-carbon), glycerol (3-carbon), erythritol (4-carbon),threitol (4-carbon), arabitol (5-carbon), xylitol (5-carbon), ribitol(5-carbon), mannitol (6-carbon), sorbitol (6-carbon), dulcitol(6-carbon), iditol (6-carbon), isomalt (12-carbon), maltitol(12-carbon), lactitol (12-carbon) or polyglycitol. A “simple sugaralcohol” is a sugar alcohol derived from a simple sugar. These termsalso cover O-acetyl derivatives thereof.

As used herein, the term “monosaccharide group” refers to a monovalentcarbohydrate group, with a carbon atom as the point of attachment. Theterm covers the groups resulting from removal of a hydroxyl radical froma simple sugar (e.g., glucose), simple deoxy sugar (e.g., fucose),simple sugar acid (e.g., gluconic acid), simple sugar alcohol (e.g.,xylitol) or simple amino sugar (e.g., glucosamine). Typically themonosaccharide group is bonded through its anomeric carbon to anothergroup (aglycone) via oxygen atom linker. In some cases the linker may bea nitrogen or sulfur atom.

A “disaccharide group” is a monovalent carbohydrate group consisting oftwo monosaccharide groups, wherein the second monosaccharide groupreplaces a hydrogen on a hydroxy group of the first monosaccharidegroup. Non-limiting examples of disaccharide groups include thosederived from sucrose, lactulose, lactose, maltose trehalose andcellobiose.

A “trisaccharide group” is a monovalent carbohydrate group consisting ofthree monosaccharide groups, wherein the second monosaccharide groupreplaces a hydrogen on a hydroxy group of the first monosaccharide groupand the third monosaccharide group replaces a hydrogen on a hydroxygroup of either the first or the second monosaccharide groups.

An oligosaccharide is a monovalent carbohydrate group consisting ofthree to ten, preferably three to six monosaccharide groups, wherein thesecond monosaccharide replaces a hydrogen on a hydroxy group of thefirst monosaccharide, the third monosaccharide replaces a hydrogen on ahydroxy group of either the first or the second monosaccharide groups,and subsequent monosaccharide groups replace hydrogens on any previouslyjoined monosaccharide groups, thus forming either a linear or branchedstructure.

The term “silyl” when used without the “substituted” modifier refers tothe group —SiR₃, where each R is independently hydrogen or unsubstitutedalkyl, as that group is defined above. The term “substituted silyl”refers to the group, —SiR₃, wherein at least one of the R groups and asmany as all of the R groups, is independently a substituted alkyl or—OH, —F, —Cl, —Br, —I, —NH₂, —NO₂, —CO₂H, —CO₂CH₃, —CN, —SH, —OCH₃,—OCH₂CH₃, —C(O)CH₃, —N(CH₃)₂, —C(O)NH₂ or —OC(O)CH₃. Any remaining Rgroups of the substituted silyl group are independently hydrogen orunsubstituted alkyl. The term “silylated” or “silanated” indicates thata given compound has been derivatized to contain a silyl and/orsubstituted silyl group. The abbreviation “-Sil” refers to silyl and/orsubstituted silyl groups.

The term “coupled” is defined as connected, although not necessarilydirectly, and not necessarily mechanically; two items that are “coupled”may be integral with each other. The terms “a” and “an” are defined asone or more unless this disclosure explicitly requires otherwise. Theterms “substantially,” “approximately,” and “about” are defined aslargely but not necessarily wholly what is specified, as understood by aperson of ordinary skill in the art.

The terms “comprise” (and any form of comprise, such as “comprises” and“comprising”), “have” (and any form of have, such as “has” and“having”), “include” (and any form of include, such as “includes” and“including”) and “contain” (and any form of contain, such as “contains”and “containing”) are open-ended linking verbs. As a result, a methodthat “comprises,” “has,” “includes” or “contains” one or more stepspossesses those one or more steps, but is not limited to possessing onlythose one or more steps. Likewise, a wound dressing that “comprises,”“has,” “includes” or “contains” one or more elements possesses those oneor more elements, but is not limited to possessing only those elements.For example, in a wound dressing that comprises a wound insert and adrape, the wound dressing includes the specified elements but is notlimited to having only those elements. For example, such a wounddressing could also include a connection pad configured to be coupled toa wound-treatment apparatus.

The term “effective,” as that term is used in the specification and/orclaims, means adequate to accomplish a desired, expected, or intendedresult.

As used herein, the term “IC₅₀” refers to an inhibitory dose which is50% of the maximum response obtained. This quantitative measureindicates how much of a particular drug or other substance (inhibitor)is needed to inhibit a given biological, biochemical or chemical process(or component of a process, i.e. an enzyme, cell, cell receptor ormicroorganism) by half.

As used herein, the term “patient” or “subject” refers to a livingmammalian organism, such as a human, monkey, cow, sheep, goat, dog, cat,mouse, rat, guinea pig, or transgenic species thereof. In certainembodiments, the patient or subject is a primate. Non-limiting examplesof human subjects are adults, juveniles, infants and fetuses.

“PBS” is phosphate buffered saline; “phr” is parts per hundred resin;“OPA” is ortho-pthaldialdehyde; “RT” is room temperature.

As generally used herein “pharmaceutically acceptable” refers to thosecompounds, materials, compositions, and/or dosage forms which are,within the scope of sound medical judgment, suitable for use in contactwith the tissues, organs, and/or bodily fluids of human beings andanimals without excessive toxicity, irritation, allergic response, orother problems or complications commensurate with a reasonablebenefit/risk ratio.

“Pharmaceutically acceptable salts” means salts of compounds which arepharmaceutically acceptable, as defined above, and which possess thedesired pharmacological activity. Such salts include acid addition saltsformed with inorganic acids such as hydrochloric acid, hydrobromic acid,sulfuric acid, nitric acid, phosphoric acid, and the like; or withorganic acids such as 1,2-ethanedisulfonic acid, 2-hydroxyethanesulfonicacid, 2-naphthalenesulfonic acid, 3-phenylpropionic acid,4,4′-methylenebis(3-hydroxy-2-ene-1-carboxylic acid),4-methylbicyclo[2.2.2]oct-2-ene-1-carboxylic acid, acetic acid,aliphatic mono- and dicarboxylic acids, aliphatic sulfuric acids,aromatic sulfuric acids, benzenesulfonic acid, benzoic acid,camphorsulfonic acid, carbonic acid, cinnamic acid, citric acid,cyclopentanepropionic acid, ethanesulfonic acid, fumaric acid,glucoheptonic acid, gluconic acid, glutamic acid, glycolic acid,heptanoic acid, hexanoic acid, hydroxynaphthoic acid, lactic acid,laurylsulfuric acid, maleic acid, malic acid, malonic acid, mandelicacid, methanesulfonic acid, muconic acid, o-(4-hydroxybenzoyl)benzoicacid, oxalic acid, p-chlorobenzenesulfonic acid, phenyl-substitutedalkanoic acids, propionic acid, p-toluenesulfonic acid, pyruvic acid,salicylic acid, stearic acid, succinic acid, tartaric acid,tertiarybutylacetic acid, trimethylacetic acid, and the like.Pharmaceutically acceptable salts also include base addition salts whichmay be formed when acidic protons present are capable of reacting withinorganic or organic bases. Acceptable inorganic bases include sodiumhydroxide, sodium carbonate, potassium hydroxide, aluminum hydroxide andcalcium hydroxide. Acceptable organic bases include ethanolamine,diethanolamine, triethanolamine, tromethamine, N-methylglucamine and thelike. It should be recognized that the particular anion or cationforming a part of any salt is not critical, so long as the salt, as awhole, is pharmacologically acceptable. Additional examples ofpharmaceutically acceptable salts and their methods of preparation anduse are presented in Handbook of Pharmaceutical Salts: Properties, andUse (P. H. Stahl & C. G. Wermuth eds., Verlag Helvetica Chimica Acta,2002).

“Prevention” or “preventing” includes: (1) inhibiting the onset of adisease in a subject or patient which may be at risk and/or predisposedto the disease but does not yet experience or display any or all of thepathology or symptomatology of the disease, and/or (2) slowing the onsetof the pathology or symptomatology of a disease in a subject or patientwhich may be at risk and/or predisposed to the disease but does not yetexperience or display any or all of the pathology or symptomatology ofthe disease.

As used herein, the term “polymer” includes “copolymers.”

A “repeat unit” is the simplest structural entity of certain materials,for example, frameworks and/or polymers, whether organic, inorganic ormetal-organic. In the case of a polymer chain, repeat units are linkedtogether successively along the chain, like the beads of a necklace. Forexample, in polyethylene, —[CH₂CH₂]_(n)—, the repeat unit is —CH₂CH₂—.The subscript “n” denotes the degree of polymerization, that is, thenumber of repeat units linked together. When the value for “n” is leftundefined or where “n” is absent, it simply designates repetition of theformula within the brackets as well as the polymeric nature of thematerial. The concept of a repeat unit applies equally to where theconnectivity between the repeat units extends three dimensionally, suchas in metal organic frameworks, modified polymers, thermosettingpolymers, etc.

The term “reticulated open cell foam” or ROCF refers to a foam materialwith a porous structure consisting of an interconnected network of solidstruts. The open cells are formed by the reticulation process, which isin turn defined as in the form of a network or having a network ofparts. Because all struts are connected, the open cell porosity is alsoconnected creating a continuously porous material. The ROCF can bedefined specifically by three independent properties; pore size,relative density, and base material. In some embodiments, ROCF is madefrom polyurethane.

The above definitions supersede any conflicting definition in any of thereference that is incorporated by reference herein. The fact thatcertain terms are defined, however, should not be considered asindicative that any term that is undefined is indefinite. Rather, allterms used are believed to describe the embodiments in terms such thatone of ordinary skill can appreciate the scope and practice theembodiments.

Further, a device or structure that is configured in a certain way isconfigured in at least that way, but it can also be configured in otherways than those specifically described.

B. Amine-Modified Materials

In one aspect, described herein, is a covalent system for attachingamine moieties to the foam, for example, the polyurethane-based foam.Such moieties can in turn be used to bind biologically activecomponents. In some case, these components can be used for catching andconcentrating specific factors in the wound environment, includingfactors that trigger a significant biological response, such asproliferation, differentiation, or angiogenesis. This technology may beused, for example, to deliver biomolecules or bioactive compounds to thewound bed. Amine-modified materials provided herein may be used in someembodiments as a system for catching and concentrating specific factorsin the wound environment, for example, factors triggering a biologicalresponse such as angiogenesis, or to deliver endogenous or exogenousbiomolecules or bioactive compounds to the wound bed.

In one aspect, the amine-modified materials and foams provided hereincomprise a polymer, such as polyurethane, copolymerized with at leastone aminoglycoside, amino sugar, amine-polyethylene glycol (amine-PEG),or amine-polyol molecule. The aminoglycoside, amino sugar, amine-PEG, oramine-polyol is covalently attached to the polymer comprising a freeamine group. In some aspects, modified materials further comprise abiologically active component attached to the functional group. It willbe further understood that such biologically active molecules can bedirectly attached to the functional group by way of a crosslinker, or athrough a crosslinker, conjugated to an adapter, which is conjugated tothe foam. The crosslinker or adapter for linking the biologically activecomponent or agent, such as a therapeutic agent, may be cleavable. Asolution, such as an instillation solution, may be employed to cleavethe therapeutic agent and deliver the therapeutic agent to the woundsite.

The biologically active agent may be covalently attached to theamine-modified foam by any physical or chemical methods including butnot limited to methods that involve temperature, pressure, pH,radiation, light, UV light, freeze-drying, and sterilization.

A list of exemplary crosslinkers are provided below in Table 1.

TABLE 1 Table shows 51 potential crosslinker chemistries that react withprimary amines. Several of these crosslinkers are cleavable, and thusthey may be used as a vehicle for delivery of molecules into the woundenvironment if they are coupled with an appropriate solution, forexample an instillation solution. Target Features Specific examplesAmine-to- NHS esters DSG; DSS; BS3; TSAT amine (trifunctional) NHSesters, BS(PEG)5; BS(PEG)9 PEG spacer NHS esters, DSP; DTSSPthiol-cleavable NHS esters, DST; BSOCOES; EGS; Sulfo- misc-cleavable EGSImidoesters DMA; DMP; DMS Imidoesters, DTBP thiol-cleavable Other DFDNBAmine-to- NHS ester/ AMAS; BMPS; GMBS and sulfhydryl MaleimideSulfo-GMBS; MBS and Sulfo-MBS; SMCC and Sulfo- SMCC; EMCS and Sulfo-EMCS; SMPB and Sulfo- SMPB; SMPH; LC-SMCC; Sulfo-KMUS NHS ester/SM(PEG)2; SM(PEG)4; Maleimide, PEG SM(PEG)6; SM(PEG)8; spacer SM(PEG)12;SM(PEG)24 NHS ester/ SPDP; LC-SPDP and Sulfo- Pyridyldithiol, LC-SPDP;SMPT; Sulfo-LC- cleavable SMPT NHS esters/ SIA; SBAP; SIAB; Sulfo-Haloacetyl SIAB Amine-to- NHS ester/ NHS-ASA; ANB-NOS; Sulfo-Nonselective Aryl Azide SANPAH NHS ester/ Sulfo-SAND Aryl Azide,cleavable NHS ester/ SDA and Sulfo-SDA; LC- Diazirine SDA andSulfo-LC-SDA NHS ester/ SDAD and Sulfo-SDAD Diazirine, cleavableAmine-to- Carbodiimide DCC; EDC Carboxyl

In one embodiment, the crosslinker for linking a biologically activemolecule to the amine-modified foam may be malondialdehyde,succinaldehyde, pthaldehyde, glutaraldehyde, or glyoxal.

In other embodiments, the biologically active molecule, such as atherapeutic agent, may be covalently attached to the polyurethane-basedfoam through a crosslinker, covalently attached to an adapter, which isconjugated to the foam. The polyurethane-based foam may not include anaminoglycoside.

Suitable Polymers

Polymers for use with the present embodiments include hydrophobic orhydrophilic polyurethanes, crosslinked and/or uncrosslinked polyolefins,polyols, ethylene vinyl acetate (EVA), elastomers such as acrylonitrilebutadiene (NBR), polychloroprene (PCP or CR), ethylene propylene rubber(EPR & EPDM), poloxamers, silicones, fluoro carbon polymers, polyvinylalcohol, polyester, polypropylene, polystyrene, polyols, poloxamer, or acombination thereof.

The foams described herein may comprise one or more copolymers. Forexample, in some embodiments, the polymer may be a polyurethane polymer.In other embodiments, the polymer may be a blend of a polyurethane andone or more other copolymers, such as polyvinyl alcohol orpolypropylene.

Polyurethanes are reaction polymers. A urethane linkage is produced byreacting an isocyanate group, —N═C═O with a hydroxy group, andpolyurethanes are produced by the polyaddition reaction of apolyisocyanate with a diol or a polyol, typically in the presence of acatalyst and other additives. A polyisocyanate is a molecule with two ormore isocyanate functional groups, R—(N═C═O)_(n), wherein n≧2 and apolyol is a molecule with two or more hydroxyl functional groups,R′—(OH)_(n), wherein ≧2. The reaction product is a polymer containingthe urethane linkage, —RNHCOOR′—. Polyurethanes may be produced byreacting a liquid isocyanate with a liquid blend of polyols, catalyst,and other additives. The blend of polyols and other additives may alsobe called a resin or a resin blend. In some aspects, the linker moietyacts in the polymerization reaction as a polyol and is thereforesubstituted for all or a portion of the polyol used in a polymerizationreaction. In some embodiments, resin blend additives may include chainextenders, cross linkers, surfactants, flame retardants, blowing agents,pigments, and/or fillers. The synthesis of breathable or air-permeable,open cell, flexible urethane polymers is taught for example by U.S. Pat.No. 5,686,501, which is incorporated by reference herein in itsentirety.

Molecules that contain two isocyanate groups are called diisocyanates.Isocyanates may be classed as aromatic, such as diphenylmethanediisocyanate (MDI), diphenylethane diisocyanate (EDI), or toluenediisocyanate (TDI); or aliphatic, such as hexamethylene diisocyanate(HDI) or isophorone diisocyanate (IPDI). An example of a polymericisocyanate is polymeric diphenylmethane diisocyanate, which is a blendof molecules with two-, three-, and four- or more isocyanate groups.Isocyanates can be further modified by partially reacting them with apolyol to form a prepolymer. A “quasi-prepolymer” is formed when thestoichiometric ratio of isocyanate to hydroxyl groups is greater than2:1. A “true prepolymer” is formed when the stoichiometric ratio isequal to 2:1. Important characteristics of isocyanates include theirmolecular backbone, % NCO content, functionality, and viscosity.

Molecules that contain two hydroxyl groups are called diols. Examplesinclude, ethylene glycol (EG), 1,4-butanediol (BDO), diethylene glycol(DEG). Molecules that contain three hydroxyl groups are called triols.Examples include glycerol. Polyols may themselves be polymers. Forexample, they may be formed by base-catalyzed addition of propyleneoxide (PO), ethylene oxide (EO) onto a hydroxy or amino-containinginitiator, or by polyesterification of a di-acid, such as adipic acid,with glycols, such as ethylene glycol or dipropylene glycol (DPG).Polyols extended with PO or EO are typically called polyether polyols.Polyols formed by polyesterification are typically called polyesterpolyols. The choice of initiator, extender, and molecular weight of thepolyol will typically affect its physical state, and the physicalproperties of the resulting polyurethane. Important characteristics ofpolyols are their molecular backbone, initiator, molecular weight, %primary hydroxyl groups, functionality, and viscosity.

One attribute of polyurethanes is their ability to be turned into foam.As the reagents react with one another, carbon dioxide gas is created,which fills and expands cells created during the mixing process. Blowingagents may also be used, including certain halocarbons such as HFC-245fa(1,1,1,3,3-pentafluoropropane) and HFC-134a (1,1,1,2-tetrafluoroethane),and hydrocarbons such as n-pentane. In some embodiments, surfactants maybe used to modify the characteristics of the polymer during the foamingprocess.

Though the properties of the polyurethane are typically determinedmainly by the choice of polyol, the diisocyanate exerts some influence.For example, the cure rate will generally be influenced by thereactivity of a given functional group and the number of functionalisocyanate groups.

Softer, elastic, and more flexible polyurethanes typically result whenlinear difunctional polyethylene glycol segments, commonly calledpolyether polyols, are used to create the urethane links. More rigidproducts typically result if polyfunctional polyols are used, as thesecreate a three-dimensional cross-linked structure which, again, can bein the form of a low-density foam. Control of viscoelastic properties,for example, by modifying the catalysts and polyols used can lead tomemory foam, which is much softer at skin temperature than at roomtemperature.

In some embodiments, the polyurethane foam is formed by thepolymerization of isocyanates and polyols, typically toluenediisocyanate and a multi arm polyether polyol. These components may beindexed, such that the isocyanate and hydroxyl group are in a one to oneratio.

Formulations of various PHR (grams of [molecule] Per Hundred grams ofpolyurethane Resin) of amine-containing molecules, such as neomycin,have been produced and tested. They have been characterized by theamount of surface amine available for bonding by conjugation of the foamwith a dye. In both cases the relative fluorescence units RFU were foundto be proportional to the primary amine available on the surface of thefoam (see FIG. 6).

In some embodiments, the foam including the polyurethane foam maycomprise an additional polymer selected from the group consisting ofpolyvinyl alcohol, polyurethane, polypropylene, polystyrene, polyols,poloxamer, or a combination of one or more of these. Accordingly, thewound dressing described herein may comprise a polymer foam comprising aone or more polymers and an aminoglycoside.

Further Modified Polymer Backbone

In some embodiments, substituted silyl-modified polymers are provided.Examples include those comprising repeat units based on polyurethane,which may be hydrophobic or hydrophilic, crosslinked and/oruncrosslinked polyolefin, polyols, ethylene vinyl acetate (EVA),elastomers such as acrylonitrile butadiene (NBR), polychloroprene (PCPor CR), amine-functionalized polyethylene glycol molecules, ethylenepropylene rubber (EPR & EPDM), silicones, and/or fluoro carbon polymers.For example, in some embodiments, an amino sugar-based polyurethanepolymers or copolymers may be used. In some embodiments, the substitutedsilyl groups are attached to the polymer or co-polymer through an oxygenatom. In other embodiments, the substituted silyl groups are attacheddirectly to a carbon atom of the polymer or co-polymer.

Some embodiments provide polymeric materials modified with silanemolecules, containing substituted silyl groups. Examples of foammaterials can include polyurethane-based foam, which may be hydrophobicor hydrophilic, including, for example an amino sugar-based polyurethanefoam material. Other foams that may be suitable include amino sugars,crosslinked and/or uncrosslinked polyolefin's, polyols, ethylene vinylacetate (EVA), and elastomers such as acrylonitrile butadiene (NBR),polychloroprene (PCP or CR), ethylene propylene rubber (EPR & EPDM),silicones, and fluoro carbon polymers. For example, in some embodiments,a amino sugars-based polyurethane foam may be used. In some embodiments,the substituted silyl groups are attached to the foam through an oxygenatom. In other embodiments, the substituted silyl groups are attacheddirectly to a carbon atom of the foam.

The silylated polyurethane foams disclosed herein may be made bysilylating the hydroxy groups on a polymer comprising such groups. Asused herein, silylation is the introduction of a substituted silyl group(R₃Si—) to a molecule. It involves the replacement of a hydrogen on thecompound, e.g., the hydrogen of a hydroxy group, with an substitutedsilyl group. Without being bound by mechanism, the oxygen atom of theproduct, may be the same oxygen atom of the hydroxy group reactant. See“How do I apply my Silane?” Gelest Catalog. 2006, pages 19-20, which areincorporated by reference herein in their entirety.

In some embodiments, the N-hydroxysuccinimide ester (NHS ester) on oneend of the Sulfo-EMCS molecule can react with free amine groups of amodified polymer. The maleimide group on the other end of the moleculemay be used to react, for example, with —SH groups on a peptide aptamerto form stable thioether bonds. In this manner the Sulfo-EMCS may beused to link the peptide to a polymer or copolymer, including a foam.

Furthermore, the peptides used in maleimide-thiol conjugation typicallyhave specially modified C-termini. For example, the C-termini may be“capped” with Cys residues bearing reactive —SH groups to facilitate theconjugation. In a Sulfo-EMCS conjugations, Sulfo-EMCS is typically usedin excess, for example, in 50-100× molar excess relative to anorganosilane crosslinkers to facilitate the reaction. Such reactions maybe carried out, for example, at pH 7.0-7.5 and at room temperature. Suchmethods may be further modified and optimized using the principles andtechniques of organic chemistry as applied by a person skilled in theart. Such principles and techniques are taught, for example, in March'sAdvanced Organic Chemistry: Reactions, Mechanisms, and Structure (2007),which is also incorporated by reference herein in its entirety. Forexample, other suitable amine-thiol linkers may be used. These include,for example: SM(PEG)24, SM(PEG)12, SM(PEG)8, SM(PEG)6, SM(PEG)4,Sulfo-LC-SMPT, SM(PEG)2, Sulfo-KMUS, LC-SMCC, LC-SPDP, Sulfo-LC-SPDP,SMPH, Sulfo-SMPB, SMPB, SMPT, STAB, Sulfo-SIAB, EMCS, Sulfo-SMCC, SMCC,MBS, GMBS, Sulfo-GMBS, Sulfo-MBS, SPDP, SBAP, BMPS, AMAS, and SIA.

In some embodiments, the silanes or aminoglycosides and/or amino sugarpolymers will be further modified with additional linker or adaptermolecules, for example, oligopeptide oligomers or an adapter of Table 1.In some embodiments, the additional linkers are covalently attached tothe backbone of the silylated or aminoglycoside and/or aminosugar-modified polymer or copolymer. In other embodiments, the linker iscovalently attached to a side chain or side group of the polymer orcopolymer. In some embodiments, the additional linker is attached via afunctional amine group of a modified-polymer or copolymer, forming amaterial.

Biologically Active Components or Agents and Modified Polymer Backbone

Described herein are wound dressings having an amine-functionalizedmaterial or foam comprising a biologically active component or agent.The biologically active component or agent may be a therapeutic agentfor treating a wound. One or more therapeutic agents may be covalentlyor non-covalently attached to the modified polymer, a polyurethane-basedfoam. The biologically active agent may be covalently or non-covalentlyattached to the material or foam through methods that involvetemperature, pressure, pH, radiation, light, UV light, freeze-drying,and sterilization.

These agents include, but are not limited to: peptides, ligands,polypeptides, peptide and protein matrices, carbohydrates, lipids,oligonucleotides, antimicrobials, small molecules, nanoparticles,nanobots, aliphatic hydrocarbon chains, surfactants, metals, andalginates, aptamers, or a combination thereof. The wound dressing may bea multifunctional dressing comprising one or more biologically activecomponents or agents. The therapeutic agent may be covalently attachedto the modified polymer via a chemical linkage.

Examples of peptides include insulin and insulin-like peptides, quorumsensing inhibitors, defensins, Cathelicidins, synthetic peptides, andpeptides that reversibly bind other peptide or protein targets.

Examples of polypeptides include extracellular matrix polypeptides,gelatin, collagen, albumin, whole or partial antibodies, C-1 complementcomponents, cytokines, growth factors, and enzymes. The enzyme may be aprotease, a kinase, or a phosphatase obtained from various sources, suchas plants or animals. The enzymes may be used for debridement, biofilmmitigation, wound healing, or a combination thereof. Some examples ofdebridement enzymes include proteases such as bromelain, papain,collagenase, and trypsin. Some examples of enzymes for biofilmmitigation include carboxypeptidase A, clostripain, and D-amino acidoxidase. Some examples of wound healing enzymes include catalases,ligases, isomerases, and hydrolases.

Examples of peptide and protein matrices include denatured andnon-denatured protein and peptide matrices. The peptide or proteinmatrix may comprise peptides, proteins, or enzymes that may becrosslinked with a linking agent. Examples of denatured peptide andprotein matrices used in this manner may include but are not limited todenatured albumin and denatured collagen. Non-denatured peptides andproteins used in this manner may include but are not limited tocytokines, growth factors, proteases, and other enzymes.

Examples of carbohydrates include but are not limited to natural orsynthetically modified monosaccharides and polysaccharides. Bothmonosaccharides and polysaccharides may be either human or microbial innature. The polysaccharide may be a mucopolysaccharide such as aglycosaminoglycan. An example of a glycosaminoglycan is heparin.

Some examples of antimicrobials include quaternary ammonium compounds,povidone-iodine, polyhexanide, antibiotics, and antimicrobialpolypeptides. An example of an antimicrobial polypeptide is LL-37.

Examples of small molecules include agonists and antagonists that maypromote wound healing. These small molecules may comprise endogenous orexogenous: mineral cofactors such as calcium, sodium, potassium, zinc,and magnesium, provided in their elemental or pharmaceutical salt form;biomolecules such as natural or synthetic regulatory peptides or peptidemimetics; drugs; metabolites of oxidative respiration; and, natural orsynthetic neurotransmitters. Examples of small molecule agonists used inthis system comprise but are not limited to, epinephrine andnorepinephrine. Examples of small molecule antagonists used in thissystem comprise but are not limited to cyclothiazide and buprenorphinehydrochloride. Examples of aptamers include dendrimers, biotin, andavidin.

In some embodiments, biologically active components or agents, includingpeptide-based aptamers, may be conjugated to a polymer or copolymer.Such polypeptides also referred to as “capture peptides”, can be used tobind protein targets in the wound environment without inhibiting theirsignaling capabilities or other functions. Such capture peptides mayalso be used to capture and increase concentrations of biologicallyactive proteins across a wound bed of a patient, for example, tostrengthen or activate a targeted biological response. These and otheruses are described in greater detail below.

In some embodiments, a linker is further connected to one or moredifferent types of active components. In some embodiments, the linker iscovalently attached to the backbone of the polymer. In otherembodiments, the linker is covalently attached to a side group of thepolymer. In some embodiments, a component, such as a polypeptide, isdirectly linked to the backbone of the polymer, forming a polymerbackbone conjugate.

When a peptide or another biologically active molecule is attached tothe other end of the silane cross linker, it will have a dissociationconstant (K_(d)), or binding affinity, that is specific to a giventarget molecule at a given set of conditions. In some embodiments, itmay allow for reversible binding of one or more target(s). In someembodiments, the aforementioned target may be released back into a woundwhen used as part of the methods and devices contemplated herein. Insome embodiments, ingredients may be added to the instillation solutionto not only help dissociate the bound factor back into the woundenvironment but to also interact synergistically with the retainedexudate element(s) for a modulating effect so that a favorable woundhealing response is elicited. Types of instillation solutions arediscussed in greater detail below.

Examples of instilled ingredients which may be used in some embodimentsto dissociate bound molecules from the peptide linkers include: salinesolutions, solutions with slightly acidic pH, slightly basic pH,solutions with various surfactants (i.e. polysorbate), EDTA or EGTA. Insome embodiments, the fluid instilled to initiate the dissociation ofthe bound factors from the linker will depend upon the binding strengthof the factor-linker complex, which is in turn determined by thedissociation constant. The dissociation constant may be modified byusing knowledge of amino acid chemistry of the factor of interest todesign a linker/peptide/aptamer.

One example of a modified dressing or wound insert is one capable ofbinding a metal, such as Ca²⁺, wound derived or otherwise, and retainingit at the wound site. During the early phases of wound healing, Ca²⁺ions are typically released from the cells locally into theextracellular space. The resulting high Ca²⁺ concentration is believedto be a positive effector of many cellular processes involved in woundhealing such as adhesion, migration and differentiation. When a highCa²⁺ concentration is required or is beneficial to the wound bed,instillation or flushing with a solution containing a chelator (e.g.,EDTA) may be used to disrupt the binding of Ca²⁺ to the dressing andinto the wound bed.

Another factor is transferrin, a blood plasma protein for iron binding.Chronic wound fluid has been shown to have significantly lowertransferrin levels indicating that oxidative stress occurs in chronicwounds. It is known that free iron can play a role in the formation offree radicals. Without being bound by theory, high levels of free ironmay contribute to exacerbation of tissue damage and delayed woundhealing. Binding and concentrating transferrin onto the dressing can beused to sequester free iron in the wound bed with subsequent releasewith an appropriate instillation solution and subsequent removal withthe exudate following the use of negative pressure. This specifictime-dependent modulation of transferring and iron levels can provide asignificant benefit to the patient. In an alternate view, the affinityof transferrin for iron is very high but is reversible in that itdecreases progressively with decreasing pH below neutrality. If a needfor localized iron concentration is necessary, instillation of a low pHsolution can be used to unbind or release iron from transferrin.

Hyaluronan, or hyaluronic acid, is another possible target contemplatedfor use. Without being bound by theory, immobilizing and concentratinghyaluronan to the wound bed before instillation with an appropriatesolution for release may be used to contribute to keratinocyteproliferation and migration and reduce collagen deposition, which inturn is known to lead to reduced scarring. Hyaluronan is also known forits free-radical scavenging function that could be beneficial as it isbound to the foam on the wound site.

Lactoferrin, known for its antimicrobial and anti-inflammatoryproperties, is another possible target for some of the embodiments.Secreted by endothelial cells, lactoferrin has been shown to have asynergistic effect with FGF2 in that there is a marked increase in theirability together to effect fibroblast migration and proliferation.Specifically designed polypeptide aptamers can be used to bind both LFand FGF2 and release them with an appropriate instillation solution inan opportune therapeutic timeframe.

TGFB-3 can be another target another possible target for some of theembodiments. This protein promotes reorganization of matrix molecules,resulting in an improved dermal architecture and reduced scarring.TGFB-3 is secreted in latent form that requires activation before it isfunctional. Activation of latent TGFB-3 occurs via binding tothrombospondin-1 (TSP-1). Therefore, TSP-1, may be used in someembodiments, as an ingredients in the instillation fluid to modulateTGFB-3 activity.

Possible other targets include calmodulin, S-100, thyroxine and cholatereceptors, amongst many others.

In some embodiments, the therapeutic agent may be a crosslinked matrix.As an example, the matrix may be a crosslinked protein matrix, whereinthe protein is an enzyme. The enzyme contains amine groups which can beused to connect enzyme molecules to each other. A crosslinker may beused to connect one enzyme molecule to another to form a matrix.Crosslinking of enzymes stabilizes, immobilizes, and protects the enzymefrom degradation by proteases. The crosslinked matrix may be covalentlyattached to the foam.

Crosslinking agents that can be used to connect enzymes to form acrosslinked enzyme matrix include glutaraldehyde, the crosslinkers ofTable I, and the crosslinker having formula (II).

Biologically active molecules, such as therapeutic agents, may becovalently attached to the foam through a crosslinker or through acrosslinker covalently attached to an adapter linked to the foam.Biologically active molecules may be attached by any physical orchemical methods. Examples of such methods may involve temperature,pressure, pH, radiation, light, UV light, freeze-drying, sterilization.

C. Uses of Modified Materials

The amine-functionalized polymeric materials discussed herein may havemany applications in both medical and non-medical use. As a material inand of itself, the polymeric product is more hydrophilic than most otherpolyurethanes due to the copolymerization of hydrophilicaminoglycosides. This allows the polymeric materials to work well incommunication with fluids. Thus, this material would provide a goodplatform for various textiles, diagnostics, protectants, andfunctionalization of various polymeric interfaces that operate with afluid medium.

The polymeric material discussed herein provides the basis for a varietyof functionalized materials and applications in the medical deviceindustry. Since the amine-functionalized polymeric material hasselective reactivity, these materials are relatively benign to livingtissues and therefore biocompatible. The combination of fluid andbiological compatibility provides a good base material for use inbiomedical devices. As such, the copolymer discussed herein couldprovide the material basis for any medical device that comes into directcontact with the tissues of a patient, including but not limited to: amedical device coating; solid or semi-solid membranes; permeable, orsemi-permeable membranes; interfacial layers, bead coatings, catheter orstent coatings, wound dressings, or any polymeric device that couldbenefit from being functionalized with the aforementioned therapeuticagents. As an example, a catheter may be coated with a functionalizedpolymeric material covalently attached with heparin.

Wound dressings provided herein comprising the amine-functionalized foamand one or more therapeutic agents may be used in various ways. As anexample, there are at least six therapeutic modalities for employing theamine-functionalized wound dressings. They include sacrificialsubstrates, antimicrobials, sequestration, mimetics, and catch andrelease using peptides, and enzymes.

When the wound dressing comprises a sacrificial substrate attached tothe foam, such as collagen, gelatin, or other protein or peptide, thewound dressing may be used to reduce matrix metalloprotein damage tohealthy tissues. Antimicrobials, such as tetrammonium compounds orantimicrobial peptides, attached to the wound dressing may be used totarget biofilms and inhibit microbial proliferation. With sequestration,critical inflammatory proteins may be sequestered or seized from thewound environment to prevent harmful biological processes. A mimetic isa molecule that imitates the structure of other important proteins inorder to influence cellular processes. The catch and release mechanismcan be carried out using peptides that are designed to trap specificprotein targets. The process involves grabbing desirable proteins fromthe wound fluid and concentrating them along the surface of the foam tobe released at a later time, for example with an instillation solution.Releasing the trapped proteins in a single bolus allows the user totrigger specific responses from the wound bed. Agents used forsequestration may comprise but are not limited to anti-sense oligomers,high affinity capture peptides, antibodies, and high affinity proteins.An example of sequestering agent is an anti-IL-1 antibody. Agents usedfor mimetics may comprise but are not limited to natural or syntheticderivatized biomolecules that resemble the epitopes of regulatory orstructural molecules; these epitopes may comprise: structural,receptor-binding, dimerizing, co-factor binding, allosteric, or activesite epitopes. An example of such an epitope mimetic is a syntheticcytokine or growth factor epitope, used to activate a cell receptor orsignal protein. An example of a catch and release peptide comprises anatural or synthetic peptide that binds to a target protein.

The wound dressing may be covalently attached with enzymes that mayperform physiological processes. The wound dressing may introduce oraugment desirable enzymatic activity in the wound environment in alocalized manner for a controlled period of time. The type of enyzmecovalently attached to the wound dressing may vary. The enzymes on thewound dressings may be useful for debridement of tissues, biofilmmitigation, or wound healing. Some examples of debridement enzymesinclude bromelain, papain, collagenase, and trypsin. Biofilm mitigationmay be based on enzymes that permanently modify bacteria-specificD-residues, such as D-amino acid oxidase, or enzymes such ascarboxypeptidase A, which specifically cleaves bacterial peptides todisrupt communication between bacterial colonies. Other enzymes that aidwound healing, such as catalases, may be used to neutralize harmfuloxygen radicals to limit ROS-mediated tissue injury. In otherembodiments, the enzymatic agent could be, but is not limited to aprotease, hydrolase, lyase, ligase, isomerase, transferase, oxidase,reductase, oxidoreductase, synthase, phosphatase, kinase, or polymerase.The wound dressing may be a multifunctional dressing comprising, forexample, a debriding agent and an anti-biofilm agent.

In one embodiment, the wound dressing comprising an amine-functionalizedpolymer and an enzyme may be used as a debridement device to removedevitalized tissue from the wound bed. In another embodiment, the wounddressing comprising an amine-functionalized polymer and an enzyme may beused with or without negative pressure wound therapy and with or withoutan instillation solution,

In other embodiments, the therapeutic agent attached to theamine-functionalized polymer may be a crosslinked enzyme matrix.Crosslinking stabilizes and protects the enzyme from degradation byother proteases. A wound dressing comprising a crosslinked enzyme matrixmay be used with negative pressure wound therapy and/or an instillationsolution or other harsh conditions without the enzyme matrix coming offin the wound environment.

The wound dressings described herein may comprise any therapeutic agent.In some embodiments the wound dressings may be used with and withoutnegative pressure wound therapy and with or without an instillationsolution.

The amine modified polymers described above and materials made therefrommay be used for a variety of purposes, including to (a) capture andconcentrate biological targets in the wound environment, (b) specify thechemical nature of the binding, and/or (c) dictate the orientation withwhich the target factors are presented to the cells. As discussed ingreater detail in the Examples section below, modified polyurethanes,including peptide modified GranuFoam™ (GF), a type of ROCF, may be usedto capture specific protein targets in vitro.

In some embodiments the modified polymers may be used to bind proteintargets in the wound environment without inhibiting their signalingcapabilities or other functions. Such modified polymers may be used aspart of a dressing or wound insert, for example, to capture and increaseconcentrations of biologically active proteins across a wound bed of apatient, for example, to strengthen or activate a targeted biologicalresponse.

In some embodiments, such a dressing may be used to concentrate proteinsof interest such as vascular endothelial growth factor in the wound bedto trigger angiogenesis and tubule formation. Additionally, antibodiesor peptides may be designed to antagonize or sequester proteins thatadversely affect the healing process, such as matrix metalloproteinasesand inflammatory mediators. Dressings made of such modified polymers maythus be used, in some embodiments, to modulate various biologicalpathways or to manage the presence of unwanted bioactive molecules orenzymes in the wound environment.

In addition to dressings, modified polymers, including those using aheterobifunctional silyl-modified linker and a polyurethane-basedpolymer or copolymer, may also be used in a wide array of othermaterials, matrixes and biomedical devices, including catheters. In suchembodiments, they may be used to conjugate a variety of biologicallyactive components, including antimicrobial compounds. The application ofthese materials to a negative pressure-based therapy is discussed ingreater detail below.

Materials may also have the advantage that they may be more efficaciousthan, be less toxic than, be longer acting than, be more potent than,produce fewer side effects than, be more easily absorbed than, and/orhave a better pharmacokinetic profile (e.g., higher oral bioavailabilityand/or lower clearance) than, and/or have other useful pharmacological,physical, or chemical properties over, compounds known in the prior art,whether for use in the indications stated herein or otherwise.

It should be recognized that the formation of variable anion and cationspecies is an expected outcome of the chemical processes describedherein, so long as the dominant species generated is pharmacologicallyacceptable.

Additional examples of pharmaceutically acceptable salts and theirmethods of preparation and use are presented in Handbook ofPharmaceutical Salts: Properties, and Use (2002), which is incorporatedherein by reference.

D. Preparation of Inserts Comprising Foam Materials Based

In another aspect, foam-based polymers may be physically and/orchemically treated, coated or manipulated before or after they arecovalently linked to an active component. Some embodiments of makingmodified wound inserts comprise: compressing (and/or felting) at least aportion of a foam. Some embodiments comprise: treating (e.g., byapplying heat, or activating a coating that has been applied to) thecompressed foam such that the foam remains substantially compressed inthe absence of an external compressive force. For example, in someembodiments, treating comprises heating the foam (e.g., foam) to anelevated temperature sufficient to reduce resiliency of the foam. Forexample, the foam can be heated to a temperature at which resiliency ofthe foam is reduced and/or relaxed, but that is below the meltingtemperature of the foam (e.g., such that the foam is not degraded by theelevated temperature). In this way, the foam can be compression setusing heat and pressure (compressive force) to relax compressive strainsdeveloped in the foam. Generally, high temperatures are used to achievethe compression set. To achieve the desired “set” such that resiliencyof the foam is reduced and/or the foam remains substantially compressedin the absence of a compressive force, temperatures can range from 158degrees Fahrenheit to 482 degrees Fahrenheit (e.g., equal to, less than,greater than, or between any of: 140, 160, 180, 200, 220, 240, 260, 280,300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500 degreesFahrenheit, depending upon the particular foam used). The foam may alsobe put through a cooling cycle to help retain the set introduced. Forexample, the foam may be cooled to a temperature below room or ambienttemperature (e.g., to or in a temperature equal to, less than, greaterthan, or between any of: 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55,60, 65, or 70 degrees Fahrenheit). In some embodiments of the presentmethods of forming a modified wound insert, the foam is disposed betweentwo heated plates or platens (e.g., in a plate or platen press and/orwhere the plates are heated to a temperature sufficient to reduce theresiliency of the foam); and the press is actuated to move the platestoward one another (e.g., perpendicular to thickness 320 of thickportions 304) such that the foam is compressed to the desired overallthickness or degree of compression). Such a press can be electrically,mechanically, and/or hydraulically operated.

Some embodiments of the present methods of making modified wound insertsalso comprise: cooling the foam (e.g., after heating the foam) such thatthe compressed portion of the foam remains substantially compressed atroom temperature (e.g., at a temperature of 72 degrees Fahrenheit) inthe absence of a compressive force. In other embodiments, cooling thefoam includes cooling a coating that has been applied to the foam suchthat the compressed portion remains substantially compressed in theabsence of a compressive force at a temperature or temperature rangeequal to, less than, greater than, or between any of: 10, 20, 30, 40,50, 60, 70, 80, 90, 100, 110, 120, 130, 140, and/or 150 degreesFahrenheit.

Thick and thin regions in the foam can be formed by any suitablemethods, such as, for example, laser cutting or the like. Such methodsare taught, for example, by U.S. Patent Application Publication2011/0178451, which is incorporated herein by reference.

In such embodiments, the coating can be dispersed through the foam, suchas, for example, by spraying the foam with the coating, dipping the foamin the coating, and/or any other suitable way of dispersing the coatingin the foam. In some embodiments, for example, the foam can be coatedwith a material that has a transition temperature (e.g., melting point,glass transition, etc.) that occurs at a relatively low temperature(e.g., lower than the foam alone), or that develops stiffness as itdries. In some embodiments, the coating can be configured to enable thefoam to be compressed (and/or compression set) at lower temperatures(e.g., without heating), such that the coating becomes stiff orotherwise resistant to expansion as it cools or dries to hold the foamin its compressed configuration. For example, a fluid adhesive may beapplied to thick portions before compressing the foam and permitted todry before removing the compressive force, such that the dried adhesivewill resist expansion from the compressed thickness. In otherembodiments, the coating can be configured to compression set the foamsuch that the compression is reversible (e.g., at least partially and/orcompletely reversible) such that the foam can expand (e.g., afterplacing in or on a wound) as it warms or absorbs water. In someembodiments, the coating comprises a cross-linkable polymer and/oractivating comprises exposing the coating to light and/or elevatedtemperature (e.g., above ambient temperature, such as, for example, atemperature sufficient to cause at least part of the cross-linkablepolymer to cross-link) to cause at least some portion of thecross-linkable polymer to become modified.

Examples of suitable coatings include cross-linkable polymers thatcontain n-methylol acrylamide (NMA). NMA is a monomer that may beco-polymerized with many other monomers (such as acrylics & vinyls). Onheating, (e.g., to about 140° C.), NMA reacts with itself and otherhydroxyl-containing groups (e.g., carboxyl). Similarly, ureaformaldehyde, melamine formaldehyde, and/or phenol formaldehyde can becaused to react with themselves and other hydroxyl-containing polymersto form crosslinks. Other crosslinking agents may include, for example,modified ethylene ureas, which react with hydroxyl-containing polymersat elevated temperatures to crosslink them. Other crosslinking agentscan include peroxides which will crosslink most polymers at elevatedtemperatures. Polymers containing hydroxyl and carboxyl groups may alsobe combined, and, when heated, may form polyester crosslinks.Additionally, epoxy prepolymers can be used that have low reactivity atroom temperatures, and when heated, react quickly to form an epoxypolymer with crosslinks. Similarly, polymeric isocyanates may be usedthat will only react significantly fast at elevated temperatures and inpresence of hydroxyl groups, amines, or moisture to form polyurethanesor polyureas.

In some embodiments, a combination of high-density regions andlow-density regions cooperate to provide various characteristics for thepresent modified wound inserts. For example, the high-density regionshave a smaller aggregate cell size and increased cell density, such thatthe high-density regions have improved wicking function andmore-effectively transmit fluid (e.g., draw fluids away from the woundsurface and/or communicate fluid from a fluid source to the woundsurface more effectively than the low-density regions. The high-densityregions are generally also mechanically stronger than the low-densityregions, such that the high-density regions can provide structuralsupport for the low-density regions and/or the modified wound insert asa whole (e.g., such that the modified wound insert is resistant totearing in directions that are not parallel to the low-density regions).Additionally, the low-density regions have a larger effective cell orpore size such that the low-density regions are less-susceptible toclogging. Especially when a negative pressure is applied to draw fluidand/or exudate away from the wound and through the modified woundinsert, the larger pore size of the low-density regions may permitfluids to be drawn through the low-density regions at a higher velocitythan the fluid is drawn through the high-density regions, such thatparticulate and granular matter are drawn to and/or through thelow-density to discourage and/or decrease the likelihood of clogging inthe high-density regions. In some embodiments, the foam can also becoated with a hydrophilic material to improve wicking properties of themodified wound insert.

The low-density regions may also be configured to permit the wounddressing to bend and/or otherwise conform to a wound. For example, thelow-density regions can be relatively easier to bend (and/or lessresilient when the modified wound insert is bent or folded along alow-density region) such as to double over a modified wound insert,and/or to conform a modified wound insert to additional hardware such asplates, pins, or the like.

Typical single-density foam modified wound inserts are isotropic suchthat under negative pressure, a typical single-density foam modifiedwound insert will contract proportionally in all directions. In someembodiments, the present modified wound inserts may also be configuredto be anisotropic, such that the present modified wound inserts can beconfigured to mechanically assist with wound closure. For example,low-density regions are less-dense (and will compress more undernegative pressure) than high-density regions. As such, if negativepressure is applied to modified wound insert, low density regions willcontract more than high-density regions, such that high-density regionswill be drawn together and modified wound insert will contract laterallymore than longitudinally. In other embodiments, the present modifiedwound inserts can be configured to have alternating and sequentiallylarger closed ring-shaped high-density regions and low-density regions,such that under negative pressure, the modified wound insert willcontract laterally inward to its own center.

In some embodiments, thick portions, thin portions, high-densityregions, and/or low-density regions can be coated and/or printed (eitherbefore or after compression) to enhance the hydrophilic or hydrophobicproperties of individual regions of the foam or of the foam as a whole.Such coated regions may also contain and/or be coated with otheradditives, such as antibiotics, or blockage-reducing agents.

In some embodiments, wound dressings comprise a wound dressingconfigured to be positioned on a wound (e.g., 26 of FIG. 1) of a patient(e.g., 30) and/or on or in contact with the wound surface (e.g., 42).

The wound dressings described herein comprising an amine-functionalizefoam may further comprise a backing or drape, covering the polymer foamsubstrate. The drape may be occlusive and may extend beyond the foam.The drape may include an adhesive portion. The adhesive portion of thebacking may extend over the foam for adhering the wound dressingdirectly to the area around the wound site. The wound dressing mayinclude an absorbant layer between the foam and the backing.

Some embodiments of the present wound-treatment methods comprise:positioning a modified wound insert (e.g., any of the present modifiedwound inserts such as 34) on a wound (e.g., 26) of a patient (e.g., 30),where the modified wound insert comprises a foam (e.g., 116). In someembodiments, the foam is sterile (e.g., substantially free of microbesand/or bacteria). Some embodiments further comprise: coupling a drape(e.g., 38) to skin (e.g., 46) adjacent the wound such that the drapecovers the modified wound insert and the wound, and forms a spacebetween the drape and the wound. Some embodiments comprise: applyingnegative pressure to the wound through the wound dressing (e.g., throughthe modified wound insert). In some embodiments, applying negativepressure to the wound comprises activating a vacuum source (e.g.,apparatus 14 of FIG. 1, or vacuum source 200 of FIG. 3) that is coupledto the wound dressing. Some embodiments comprise: delivering a fluid tothe wound through the wound dressing. In some embodiments, delivering afluid comprises activating a fluid source (e.g., fluid source 248 ofFIG. 3) that is coupled to the wound dressing.

Some embodiments of the present wound-treatment systems comprise eitherembodiment of system 10 (or any subset of components of eitherembodiment of system 10), and one or more of the present modified woundinserts and/or wound dressings.

The various illustrative embodiments of devices, systems, and methodsdescribed herein are not intended to be limited to the particular formsdisclosed. Rather, they include all modifications and alternativesfalling within the scope of the claims.

The claims are not intended to include, and should not be interpreted toinclude, means-plus- or step-plus-function limitations, unless such alimitation is explicitly recited in a given claim using the phrase(s)“means for” or “step for,” respectively.

It will be understood that the benefits and advantages described abovemay relate to one embodiment or may relate to several embodiments. Itwill further be understood that reference to ‘an’ item refers to one ormore of those items, unless otherwise specified.

The steps of the methods described herein may be carried out in anysuitable order, or simultaneously where appropriate.

Where appropriate, aspects of any of the examples described above may becombined with aspects of any of the other examples described to formfurther examples having comparable or different properties andaddressing the same or different problems.

It will be understood that the above description of preferredembodiments is given by way of example only and that variousmodifications may be made by those skilled in the art. The abovespecification, examples and data provide a complete description of thestructure and use of exemplary embodiments. Although various embodimentshave been described above with a certain degree of particularity, orwith reference to one or more individual embodiments, those skilled inthe art could make numerous alterations to the disclosed embodimentswithout departing from the scope of the present disclosure.

E. Devices Comprising an Modified Wound Insert

The modified polymers described above and materials made therefrom maybe used for a variety of purposes, including to (a) capture andconcentrate biological targets in the wound environment, with the optionto release back into the wound bed, (b) specify the chemical nature ofthe binding, and/or (c) dictate the orientation with which the targetfactors are presented to the cells.

A dressing or wound insert made for an modified polymer may be usedtogether with negative pressure wound therapy. In some embodiments,compatible foam coated with aptamers or small peptide linkers (ligands)which select for beneficial molecules in the wound fluid as it passesthrough the foam would thereby prevent their removal into the negativepressure wound therapy canister. Appropriate molecules for selectionfrom wound fluid include metabolites, growth factors, chemokines andcytokines which would not impede fluid flow through the negativepressure wound therapy dressing. In some embodiments, appropriatelinkers would bind the wound fluid molecules in such an orientation thatthe “active site” of the wound fluid molecule is still available foreliciting a biological response. For example, one such molecule may beVEGF. VEGF has specific sites on the molecule that bind to cellularreceptors. The binding of the VEGF molecule to the cellular receptor maybe used to initiate a biological response, typically angiogenesis.

In some embodiments, the methods taught herein may be used to bind tomolecules chemotactic to macrophages such as MCP1, which may be used tostimulate macrophage migration into the wound and thereby progress thewound from a chronic to a healing state. In some embodiments, PDGF orcollagen fragments could be bound during the proliferative or lateinflammatory phases to stimulate the migration of fibroblasts into thewound. Stimulating the migration of macrophages and then fibroblastsinto the wound may assist in the progression of the wound through theinflammatory phase and into the proliferative phase of wound healing. Insome embodiments, Nitric Oxide Synthase could be bound from the woundfluid to stimulate perfusion. This may help to promote healing byallowing a higher level of nutrients into the wound. In someembodiments, anti-inflammatory cytokines such as IL4 or IL10 could bebound to decrease inflammation, thus progressing the wound more quicklythrough the inflammatory and into the proliferative phase of healing.DNA fragments could also be bound to the dressing. In some embodiments,the binding of highly charged DNA could enable current to be passedthrough the dressing. Electrical stimulation has been used for manyyears in the treatment of wounds. Therefore, binding DNA to the wounddressing may allow for the application of current to the wound.

Referring now to the drawings, and more particularly to FIG. 1, showntherein is an embodiment of one of the present wound treatment system10. In the embodiment shown, apparatus 10 comprises a wound-treatmentapparatus 14, and a wound dressing 18 coupled to apparatus 14 by aconduit 22. As shown, dressing 18 is configured to be coupled to (and isshown coupled to) a wound 26 of a patient 30. More particularly, in theembodiment shown, dressing 18 comprises a modified wound insert 34 and adrape 38. As shown, modified wound insert 34 is configured to bepositioned (and is shown positioned) on wound 26 (e.g., on or adjacentto wound surface 42), and/or drape 38 is configured to be coupled to(and is shown coupled to) skin 46 of the patient adjacent to wound 26such that drape 38 covers modified wound insert 34 and wound 26, andforms a space 50 between drape 38 and wound 26 (e.g., wound surface 42).

Apparatus 14 can comprise, for example, a vacuum source configured to beactuatable (and/or actuated) to apply negative pressure (e.g., viaconduit 22) to wound dressing 18, a fluid source configured to beactuatable (and/or actuated) to deliver (e.g., via conduit 22) a fluid(e.g., an installation fluid such as a medicinal fluid, antibacterialfluid, irrigation fluid, and or the like) to wound dressing 18. System10 can be implemented and/or actuated and/or coupled to patient 30 inany of various configurations and/or methods similar to those describedin the prior art. For example, various wound therapy systems andcomponents are commercially available through and/or from KCI USA, Inc.of San Antonio, Tex., U.S.A., and/or its subsidiary and relatedcompanies (collectively, “KCI”).

Conduit 22 can comprise a single lumen conduit (e.g., switched between avacuum source and/or a fluid source and apparatus 14), or can comprisemultiple single-lumen conduits or a multi-lumen conduit such that, forexample, fluid can be delivered and/or negative pressure can be appliedto wound dressing 18 individually and/or simultaneously. Additionally,conduit 22 can comprise, for example, a first lumen for the applicationof negative pressure and/or fluid delivery, and at least one additionallumen for coupling to pressure sensor(s) to sense pressure or negativepressure between drape 38 and surface 42. In some embodiments, conduit22 can comprise multiple lumens (e.g., as in a single conduit with acentral lumen for application of negative pressure and/or fluiddelivery, and one or more peripheral lumens disposed adjacent or aroundthe central lumen such that the peripheral lumens can be coupled to apressure sensor to sense a pressure or negative pressure between drape38 and surface 42 (e.g. in space 50). The lumens may be arranged with acentral lumen and other lumens disposed radially around the centrallumen, or in other suitable arrangements. The lumens may also beprovided in separate conduits. In the embodiment shown, system 10further comprises a wound dressing connection pad 54 configured to becoupled (and is shown coupled) to conduit 22. One example of a suitableconnection pad 54 is the “V.A.C. T.R.A.C.® Pad,” commercially availablefrom KCI. One example of a suitable drape 38 includes the “V.A.C.®Drape” commercially available from KCI.

Referring now to FIG. 2, a side view of a modified wound insert 34 isshown. Modified wound insert 34 has an upper side 100, a lower side 104,lateral sides 108, 112 and interior volume 116. Although only one sideis shown of modified wound insert 34, it will be understood by those ofordinary skill in the art that modified wound insert 34 includes athree-dimensional rectangular volume having a depth extendingperpendicular to the side shown. In other embodiments, modified woundinsert 34 can have any suitable shape, such as, for example, a roundcylindrical shape, a fanciful shape, or may be trimmed to fit anirregular shape of a wound (e.g., 26 and/or wound surface 42). Modifiedwound insert 34 can comprise a foam, such as, for example, open-celledfoam (which may also be reticulated).

Embodiments of the present wound treatment methods may be betterunderstood with reference to FIG. 1, which depicts a schematic blockdiagram of one embodiment of system 10. In the embodiment shown, wounddressing 18 is coupled to apparatus 14, and apparatus 14 comprises avacuum source 200 (e.g., a vacuum pump and/or the like) coupled to acanister 204 (e.g., configured to receive exudate and or the like fromwound dressing 18) by way of a conduit 208. In the embodiment shown,apparatus 14 further comprises: a pressure sensor 212 having a firstpressure transducer 216 coupled to conduit 208 by way of conduit 220and/or tee-fitting 224, and a second pressure transducer 228 coupled tocanister 204 and/or wound dressing 18 by way of conduit 232. Pressuresensor 212 is configured to sense the negative pressure in wounddressing 18, and/or any of the various lumens (e.g., within conduits)coupled to wound dressing 18, pressure sensor 212, and/or vacuum source200.

In the embodiment shown, apparatus 14 further comprises a pressurerelease valve 236 coupled to conduit 232. Further, in the embodimentshown, canister 204 and vacuum source 200 are coupled to wound dressing18 by way of conduit 240; and/or canister 204 can comprise a filter 244at or near an outlet of canister 204 to prevent liquid or solidparticles from entering conduit 208. Filter 244 can comprise, forexample, a bacterial filter that is hydrophobic and/or lipophilic suchthat aqueous and/or oily liquids will bead on the surface of the filter.Apparatus 14 is typically configured such that, during operation, vacuumsource 200 will provide sufficient airflow through a filter 244 that thepressure drop across filter 244 is not substantial (e.g., such that thepressure drop will not substantially interfere with the application ofnegative pressure from wound dressing 18 from vacuum source 200).

In the embodiment shown, apparatus 14 further comprises a fluid source248 coupled to wound dressing 18 by way of a conduit 252 that is coupledto conduit 240 such as, for example, by way of a tee- or other suitablefitting 256. In some embodiments, tee fitting 256 can comprise a switchvalve and/or the like such that communication can be selectivelypermitted between wound dressing 18 and vacuum source 200, or betweenwound dressing 18 and fluid source 248. In some embodiments apparatus 14comprises only one of vacuum source 200 and fluid source 248. Inembodiments of apparatus 14 that comprise only fluid source 248,canister 204 and/or pressure sensor 212 can also be omitted. In variousembodiments, such as the one shown, conduit 232 and/or conduit 240and/or conduit 252 can be combined and/or comprised in a singlemulti-lumen conduit, such as is described above with reference toFIG. 1. In some embodiments, fluid source 248 is coupled directly towound dressing 18 (e.g., conduit 252 is coupled one end to wounddressing 18, such as via connection pad 54, and conduit 252 is coupledon the other end to fluid source 248; and conduit 252 is not coupled totee fitting 256).

In various embodiments, such as the one shown in FIG. 3, apparatus 14can be configured such that as soon as liquid in the canister reaches alevel where filter 244 is occluded, a much-increased negative (orsubatmospheric) pressure occurs in conduit 208 and is sensed bytransducer 216. Transducer 216 can be connected to circuitry thatinterprets such a pressure change as a filled canister and signals thisby means of a message on an LCD and/or buzzer that canister 204 requiresemptying and/or replacement, and/or that automatically shuts off ordisables vacuum source 200.

Apparatus 14 can also be configured to apply negative (orsubatmospheric) pressure (e.g., continuously, intermittently, and/orperiodically) to the wound site, and/or such that pressure relief valve236 enables pressure at the wound site to be brought to atmosphericpressure rapidly. Thus, if apparatus 14 is programmed, for example, torelieve pressure at ten-minute intervals, at these intervals pressurerelief valve 236 can open for a specified period, allow the pressure toequalize at the wound site, and then close to restore the negativepressure. It will be appreciated that when constant negative pressure isbeing applied to the wound site, valve 236 remains closed to preventleakage to or from the atmosphere. In this state, it is possible tomaintain negative pressure at the wound site without running and/oroperating pump 200 continuously, but only from time to time orperiodically, to maintain a desired level of negative pressure (i.e. adesired pressure below atmospheric pressure), which is sensed bytransducer 216. This saves power and enables the appliance to operatefor long periods on its battery power supply.

In some embodiments, factors may be removed, or their concentrationmodulated, using electrical pulses, light, ultrasound and temperature.

F. Instillation Solutions

In some embodiments dressing made from the amine modified polymersdisclosed herein may be used together with wound instillation solutions,for example in the application of a negative pressure treatment to apatient's wound. In some embodiments, the instillation solutioncomprises ingredients to help release or modulate the release of thefactors bound to the foam to the wound site.

Examples of instilled ingredients which may be used in some embodimentsto dissociate bound molecules include: saline solutions,pharmaceutically acceptable salt solutions, Dakin's solutions, PHMBsolutions, acetic acid, zwitterionic detergent solutions, solutions withslightly acidic pH, solutions with slightly basic pH, solutions withvarious surfactants (i.e. tween, SDS, polysorbate), solutions withslight ionic charge, EDTA, or EGTA. In some embodiments, the fluidinstilled to initiate the dissociation of the bound factors from thelinker will depend upon the binding strength of the factor-linkercomplex, which is in turn determined by the dissociation constant. Thedissociation constant may be modified by using knowledge of amino acidchemistry of the factor of interest to design the linker/peptide.

In some embodiments, the instillation solution comprises hypochlorousacid (HOCl) and hypochlorite ion. Both are examples of effectiveantimicrobial agents for biocidal action. For example, HOCl is typicallycapable of killing a broad spectrum of microbes (e.g., fungus, bacteria,viruses, fungus, yeast, and the like); often in a relatively shortperiod of time (e.g., is capable of killing greater than 99% of microbeswithin a period of less than 10 seconds). Such antimicrobial agents canbe generated or formed by a combination of the present reactive agentsand fluid (e.g., water and/or aqueous solution, such as, for example,saline solution) and may be more effective and/or more versatile thanantibiotics and other commonly used antimicrobial agents used in woundtreatment in the past. For example, antibiotics may be bacteria-specificsuch that testing may be required to determine a suitable antibiotic touse for a specific wound or infection; and/or such that antibiotics mayhave only limited effectiveness for individual wounds and/or infections(e.g., where testing is not performed and/or where a wound is infectedwith a plurality of different bacteria). Such testing may take as longas several days to determine an appropriate antibiotic, delayingtreatment or selection of an effective antibiotic. Additionally,bacteria may develop resistance to antibiotics, such that antibioticsmay have reduced effectiveness after an amount of time. Further,antibiotics are typically administered intravenously (systemically) suchthat antibiotics may kill beneficial bacteria (e.g., in a patient'sdigestive system) and/or may cause organ damage (e.g., to a patient'sliver).

In contrast, the reactive agents (and/or antimicrobial products of thereactive agents) of the present embodiments can be configured to have abroad-spectrum killing power that will kill a variety of microbes (e.g.,fungus, bacteria, viruses, fungus, yeast, etc.). Additionally, thepresent reactive agents (and/or antimicrobial products of the reactiveagents) can be delivered locally (preventing systemic damage or otherside effects to organs and the like).

However, due to the reactivity of HOCl or OCl⁻ with oxidizable organicsubstances, its utility in wound care applications has previously beenlimited. For example, prior art methods of generating hypochlorous acidhave required electrolysis of saltwater or the like (e.g., withexpensive equipment at a patient's bedside). By way of another example,commercially available chemicals (e.g., bleach) have a hypochlorous acidconcentration of 5% or greater, which is too high to permit medical uses(e.g., will cause cytoxicity). Additionally, at suitable medicalconcentrations (e.g., 2-20 mM hypochlorous acid solutions),approximately 99% or more of the solution is water, such that shippingis more expensive and/or more difficult than necessary. Further, storageof hypochlorous acid solutions is difficult, as reactions withcontainers typically degrade or reduce the concentration of thehypochlorous acid solution. However, the present wound inserts can bedeposited with reactive agents (have reactive agents deposited in thefoam of the wound inserts) such that upon application of a fluid such assaline or water, OCl (and/or ClO⁻) is released (e.g., to formhypochlorous acid) and delivered to a wound for biocidal action.

EXAMPLES

The following examples are included to demonstrate preferredembodiments. It should be appreciated by those of skill in the art thatthe techniques disclosed in the examples which follow representtechniques discovered by the inventor to function well in the practiceof the products, compositions, and methods described herein, and thuscan be considered to constitute preferred modes for its practice.However, those of skill in the art should, in light of the presentdisclosure, appreciate that many changes can be made in the specificembodiments which are disclosed and still obtain a like or similarresult without departing from the spirit and scope of the disclosure.

Example 1—Preparation of Amine-Functionalized Polyurethane Foam

In the construction of this new foam material, neomycin (FIG. 4), anaminoglycoside, was co-polymerized with a polyol into a toluenediisocyanate backbone, producing a white, reticulated open celled foam(FIG. 5) that withstood 40 Kgy gamma sterilization. The neomycinmodified foam also had good tensile strength and absorbed and retainedwater.

The 0.001-40 phr Neomycin foam prototypes showed reactivity with theirprimary amine groups. The reactivity of the amine groups was verified byincubating the foams with a dye that binds to primary amine groups. Themore amine, the more fluorescence observed due to the dye. After bindingthe dye, the foams were measured for fluorescence and photographed inthe fluorescent microscope (FIG. 6). The relative fluorescence unitsobserved by fluorometer and the photos collected by fluorescentmicroscopy provided evidence of the amine functionality of the foam.When measured by fluorescence, the 10 phr neomycin foam had the highestamine content, 74868 RFUs. It is important to point out that this wastwice the amount of RFU's observed with the 30 phr chitosan foam made bya professional foam manufacturer. 5 phr neomycin yielded 43632 RFUs,which was also substantially better than 36562 RFUs produced by thechitosan foam. The Base Polyurethane in this study consisted of polyoland TDI (no amines), so it was used as a negative control and yielded7591 RFUs. At 15 phr, neomycin began to aggregate forming a paste thatdid not disperse well, thus the polymerization was poor. Thus, an idealneomycin range may be between about 0-40 phr.

Neomycin polymerizes well with isocyanate chemistry due to the —OHgroups and amine groups that allow it to copolymerize with the toluenediisocyanate. When the reaction occurs, the —OH and —NH2 groupspolymerize with isocyanate, but a significant portion of the primary theprimary amine groups (NH₂) remain accessible for further chemicalreactions. Leaving the amines accessible is important because it willenable the crosslinker chemistries depicted in Table 1 above arepossible adaptor molecules that can used for linkage of variousbiologically active compounds (e.g., proteins) to the modified foams. Tosummarize Table 1, amine functionalization of foams will allow for awide array of novel crosslinker chemistries that can be used to furthermodify the foam.

Example 2: Amine-Functionalized Polyurethane Foam Containing Bromelain(Enzyme Protease Dressing (EPD))

The co-polymer was made by combining water, toluene diisocyanate,aminoglycoside, polyol, surfactant, and catalysts. Once polymerizationwas complete, the foam was cured and washed with deionized water. Nextthe therapeutic protein matrix was crosslinked and conjugated to thefoam, creating the EPD. The EPD was subsequently washed and subjected toseveral physical and biochemical tests.

Analysis

The testing regimen for the EPD consisted of scanning electronmicroscopy (SEM, FIG. 7), biochemical tests (FIG. 8), and physical modeltests. First, 250× photos of the enzyme-coated foams were collected toconfirm the absence or presence of the coating. Second, biochemicaltests were performed to measure the functionality of the enzymes aftercrosslinking. Next, EPD prototypes were applied to tissue models toobserve proteolytic activity.

SEM Analysis of the EPD

Images of the coated and uncoated foams with the SEM at 250× wereobtained. FIG. 7A shows uncoated amine functionalized polyurethane foamsubstrate with smooth struts and surfaces. FIG. 7B shows theamine-functionalized polyurethane foam substrate with a covalently boundenzyme matrix (arrows). The enzyme matrix appears as coarse plaques thatcoat the foam surface. FIG. 7B confirms that the amine-functionalizedfoam is covalently coated with the enzyme.

Biochemical Tests

Bromelain is a cysteine protease enzyme that cuts proteins and peptidesat specific amino acid sequences. EPD performance was measured in abiochemical assay against a published cysteine protease substrate. Inthis format, the bromelain cuts the substrate, making the substratechange into a yellow color. As more substrate is cut, more yellow colordevelops. The extent of the color formation (spectrophotometry at OD412) can be measured to describe the amount of cutting performed by theenzyme. FIG. 8 compares EPD activity with bromelain standard. EPDperformed roughly equivalent to the 6.25 uM bromelain standard. Thestandards were prepared by dissolving crude Bromelain powder in reactionbuffer and testing the solutions against the substrate. Consequently,these data indicate that the covalently bound bromelain enzyme wasfunctional after crosslinking to the foam.

Physical Model Tests

The physical model is a useful tool for visualizing the proteolyticactivity of the EPD. Briefly, the EPD was applied to prepared pig skinand photos were taken before and after. Next, the wounds were treatedovernight with a negative control foam and the EPD, respectively, andthen photos were taken again. A comparative analysis of the photosshowed that the EPD imparted more proteolytic activity upon the pigtissues than the negative control.

All publications, patents and patent applications cited in thisspecification are incorporated herein by reference in their entiretiesas if each individual publication, patent or patent application werespecifically and individually indicated to be incorporated by reference.While the foregoing has been described in terms of various embodiments,the skilled artisan will appreciate that various modifications,substitutions, omissions, and changes may be made without departing fromthe spirit thereof.

1. A wound dressing comprising an amine-functionalized polymer foam anda biologically active agent attached to an amine group on the polymerfoam.
 2. The wound dressing of claim 1, wherein the biologically activeagent is attached to the foam through an adapter.
 3. The wound dressingof claim 1, wherein the biologically active agent is a polypeptide. 4.The wound dressing of claim 3, wherein the polypeptide is selected fromthe group consisting of gelatin, collagen, albumin, an enzyme, growthfactor, chemokine, cytokine, and a polypeptide that binds to any ofthem.
 5. The wound dressing of claim 4, wherein the polypeptide is anenzyme selected from a protease, hydrolase, lyase, ligase, isomerase,transferase, oxidase, reductase, oxidoreductase, synthase, polymerase,kinase, and phosphatase.
 6. The wound dressing of claim 1, comprising apolyurethane foam.
 7. The wound dressing of claim 6, comprising an opencell foam.
 8. The wound dressing of claim 1, wherein theamine-functionalized polymer foam comprises a polyurethane polymercopolymerized with neomycin.
 9. The wound dressing of claim 1, whereinthe biologically active agent is directly attached to the functionalizedpolymer foam.
 10. The wound dressing of claim 2, wherein the adapter isan amine to amine crosslinker.
 11. The wound dressing of claim 10,wherein the amine-to-amine crosslinker is selected from malondialdehyde,succinaldehyde, phthalaldehyde, glutaraldehyde, and glyoxal.
 12. Thewound dressing of claim 11, wherein the crosslinker is glutaraldehyde.13. The wound dressing of claim 2, wherein the adapter is cleavable. 14.The wound dressing of claim 7, wherein the material comprises a foamthat is a reticulated open-celled foam.
 15. A method for treating awound site, comprising: applying a wound dressing according to claim 1to a wound site; and applying negative pressure to the wound site. 16.The method of claim 15, further comprising applying an instillationsolution to the wound site.
 17. The method of claim 15, wherein thebiologically active agent comprises a polypeptide.
 18. The method ofclaim 16, wherein the instillation solution includes one or more agentsthat modulate a release of the biologically active agent.